SECTION 9E
INSTRUMENTATION/DRIVER INFORMATION
Caution : Disconnect the negative battery cable before removing or installing any electrical unit or when atool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cablewill help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unlessotherwise noted.
SPECIFICATIONS
Fastener Tightening Specifications
Application | N•m | Lb-Ft | Lb-In |
Front Console Screws | 2 | - | 18 |
Driver Information Center Screws | 2 | - | 18 |
Cluster Illumination Connector Screws | 2 | - | 18 |
Digital Clock Screws | 2 | - | 18 |
Instrument Cluster Screws | 2 | - | 18 |
Instrument Panel Lower Compartment Screws | 2 | - | 18 |
Instrument Panel Steering Column Opening Pillar Screws | 2 | - | 18 |
Instrument Panel Compartment Screws | 2 | - | 18 |
Dimmer/Headlamp Leveling/Mirror Control Switch Screw | 2 | - | 18 |
Instrument Panel-to-Body Bolts | 23 | 17 | - |
Steering Column Bolts | 22 | 16 | - |
Steering Column Nuts | 22 | 16 | - |
SCHEMATIC AND ROUTING DIAGRAMS
Driver Information Center & Digital Clock
Instrument Cluster Meters and Gauges
Instrument Cluster
Instrument Panel Illumination
DIAGNOSIS
Symptoms - Instrument Panel, Gauges
Important : The following steps must be completed before using the symptom tables.
- Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following are true:
- There are no DTCs set.
- The control modules can communicate via the serial data link.
- Review the system operation in order to familiarize yourself with the system functions.
Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the Instrument Cluster or Audible Warning Systems.
- Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
- Inspect for proper fluid level.
Intermittents
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Section 9A, Body Wiring System.
Instrument Cluster Inoperative
Diagnostic Fault Information
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
Voltage is supplied to the instrument panel cluster (IPC) through the battery voltage circuit and the ignition 1 voltage circuit. The IPC will operate when the ignition 1 voltage circuit is in the RUN/START position.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
- Ignition OFF, disconnect the IPC.
- Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit and a ground.
- If the test lamp does not illuminate, repair the ignition 1 voltage circuit for a short to ground or an open/high resistance.
- Verify that a test lamp lamp illuminates between the ignition 1 voltage circuit and the IPC ground circuit.
- If the test lamp does not illuminate, repair the IPC ground circuit for an open/high resistance.
- If the test lamp does illuminate, replace the IPC.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for IPC and PCM replacement, setup, and programming.
Engine Coolant Temperature Gauge Inaccurate or Inoperative
Diagnostic Fault Information
Important : Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the engine control module (ECM). The ECM sends the temperature data via GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the IPC in order to control the engine temperature gauge and display the engine temperature.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
Ignition ON, perform the engine coolant gauge sweep test with the scan tool.
- If the engine coolant gauge does not sweep from its low to high position, replace the instrument panel cluster (IPC).
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for IPC replacement, setup, and programming.
Fuel Gauge Inaccurate or Inoperative
Diagnostic Fault Information
Important : Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank.
The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gauge. Then fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
- Ignition OFF, disconnect CXXX, install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
- Ignition ON, vary the resistance on the signal generator from 40-250 ohms and monitor the fuel gauge.
- If the fuel gauge displays the correct fuel level, test the signal circuit for an open/high resistance between CXXX and the fuel level sender. If the circuit tests normal, test the low reference circuit for an open/high resistance between CXXX and the fuel level sender.
- If all circuits test normal, replace the fuel level sender.
- Ignition ON, vary the resistance on the signal generator from 40-250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays the correct fuel level percent.
- If the fuel level percent is correct, replace the instrument panel cluster (IPC).
- If the fuel level percent is incorrect, test the signal circuit for an open/high resistance. If the circuit tests normal, test the low reference circuit for an open/high resistance.
- If all circuits test normal, replace the ECM.
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Fuel Level Sensor Replacement or Fuel Level Sensor Replacement or Fuel Level Sensor Replacement or Fuel Level Sensor Replacement in Section 1F2, Engine Controls-FAM II 2.4D
Speedometer and/or Odometer Inaccurate or Inoperative
Diagnostic Fault Information
Important : Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The instrument panel cluster (IPC) displays the vehicle speed based on the information from the engine control module (ECM). The ECM converts the data from the vehicle speed sensor to a 4000 pulses/mile signal. The PCM sends the vehicle speed information via GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the IPC in order to control the speedometer gauge and display the vehicle speed and miles traveled.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
- Ignition OFF, raise the vehicles drive wheels.
- Engine ON, transmission in drive, verify the scan tool Vehicle Speed Sensor parameter matches the speedometer display.
- If the Vehicle Speed Sensor parameter does not match the speedometer display, replace the IPC.
- If the odometer is not operating properly, replace the IPC.
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Tachometer Inaccurate or Inoperative
Diagnostic Fault Information
Important : Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The instrument panel cluster (IPC) displays the engine speed based on the information from the engine control module (ECM). The ECM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The ECM sends the engine speed information via GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the IPC in order to control the tachometer gauge and display the engine speed.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
Ignition OFF, raise the vehicles drive wheels.
- If the tachometer gauge does not sweep from its low to high position, replace the instrument panel cluster (IPC).
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Chime Always On
Diagnostic Fault Information
Important : Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The radio generates the audible warning through the left front speaker. The radio receives audible warning requests via GMLAN serial data from the body control module (BCM).
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Testing
- Ignition ON, headlamp switch OFF, verify the scan tool Headlamp Switch parameter is Inactive.
- If not Inactive, test the headlamps signal circuit for an open or short to voltage. If the circuit tests normal, replace the headlamp switch.
- Ignition OFF, key out of the ignition, verify the scan tool Key In Ignition Status parameter is Key Out.
- If not Key Out, test the key in ignition switch signal circuit for an open or short to voltage. If the circuit tests normal, replace the ignition switch.
- Ignition OFF, key out of the ignition, verify the scan tool Key In Ignition Status parameter is Key Out.
- If any parameter displays Door Ajar, go to Courtesy Lamps Always On.
- If all parameters display Door Closed, replace the BCM.
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Ignition Switch Replacement
- Multifunction, Turn Signal Switch Replacement
Diagnostic Trouble Code (DTC) U0073
Control Module Communication Bus Off
Circuit Description
The GMLAN serial data circuits are controller area network (CAN) High and/or Low speed serial data buses used to communicate information between the control modules. Typical data transmission speeds must be high enough to ensure that a required real-time response is maintained.
There are two different types of GMLAN serial data circuits, the High speed 2-wire circuit and Low speed single wire circuit. The GMLAN serial data circuits also communicate directly to the data link connector (DLC). Messages are interpreted by the externally connected CANdi module which acts as a transceiver for the scan tool.
DTC U0073 Will Set When
The module setting the DTC has attempted to establish communications on the GMLAN circuits for more than 7 times.
Conditions for Setting the DTC
- Any of the low speed GMLAN serial data circuits shorted to ground or voltage.
- A module internal malfunction that causes a short to voltage or ground on the low speed GMLAN circuits
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn OFF the ignition.
- Perform the Vehicle DTC Information function on the scan tool.
Does the scan tool communicate with any module on the low speed GMLAN serial data circuit? | - | Go to Step 3 | Go to Step 5 |
| 3 | Did you record any DTCs among U0140 and U0155? | - | Go to related DTC diagnosis | Go to Step 4 |
| 4 | Check for an open and short to ground or voltage of the low speed GMLAN serial data circuit communicating with each module. Did you find and correct the condition? | - | Go to Step 16 | Go to Step 5 |
| 5 | - Check for an open or short to ground of the ignition and battery circuit to the BCM.
- Check for an open of the ground circuit to the BCM.
Did you find and correct the condition? | - | Go to Step 13 | Go to Step 6 |
| 6 | - Turn OFF the ignition.
- Disconnect the scan tool from the data link connector(DLC).
- Check for poor a connection at the terminal 1 of DLC connector.
Did you find and correct the condition? | - | Check the vehicle with the scan tool. | Go to Step 7 |
| 7 | - Disconnect the farthest module from the DLC that is connected to low speed GMLAN serial data circuit.
- Turn ON the ignition.
- Attempt to communicate with the BCM.
Does the scan tool communicate with the BCM? | - | Go to Step 11 | Go to Step 8 |
| 8 | - Turn OFF the ignition.
- Disconnect the farthest module from the DLC that is still connected to low speed GMLAN serial data circuit.
- Turn ON the ignition.
- Attempt to communicate with the BCM.
Does the scan tool communicate with the BCM? | - | Go to Step 9 | Go to Step 10 |
| 9 | Check for a short to ground or voltage of the low speed GMLAN serial data circuit between the last two disconnected modules. Did you find and correct the condition? | B+ | Go to Step 9 | Go to Step 10 |
| 10 | Is the BCM the last module still connected to low speed GMLAN data circuit? | - | Go to Step 11 | Go to Step 8 |
| 11 | - Turn OFF the ignition.
- Disconnect the BCM.
- Check for an open and a short to ground or voltage of the low speed GMLAN serial data circuit between BCM and the previous disconnected module and between BCM and DLC.
Did you find and correct the condition? | - | Go to Step 14 | Go to Step 12 |
| 12 | Check for poor connections at the low speed GMLAN serial data circuit of the last disconnected module. Did you find and correct the condition? | - | Go to Step 14 | Go to Step 13 |
| 13 | Replace the last disconnected module. Did you complete the replacement? | - | Go to Step 14 | - |
| 14 | - Reconnect all of the disconnected modules.
- Install a scan tool.
- Turn ON the ignition, with the engine OFF.
- Wait for 10 seconds. The scan tool may require a power up reset before communication will occur due to a short on the low speed GMLAN serial data circuits. Turn OFF or disconnect the scan tool prior to performing this test.
- Select the Display DTCs function for each module.
- Record all of the displayed DTCs and the DTC status.
Did you record any DTCs which begin with a "U" and with a current status? | - | | Go to Step 15 |
| 15 | Did you record any DTCs which do not begin with a "U"? | - | | Go to Step 16 |
| 16 | Did you diagnose all of the DTCs? | - | Go to Step 17 | Go to Step 14 |
| 17 | Use the scan tool in order to clear the DTCs. Did you complete the action? | - | System OK | - |
Diagnostic Trouble Code (DTC) U0140
Lost Communication With BCM
Circuit Description
Modules connected to the GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have programmed information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are also supervised and some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 milliseconds. Each message contains the identification number of the transmitter module. When a message that indicates the availability of the transmitter module is not received, the receiver module sets a DTC U01xx where xx is equal to the 2-digit identification number of the transmitter module.
A module with a GMLAN serial data circuit malfunction or which loses power during the current ignition cycle will have a Lost of Communication DTC set by other modules that depend on information from that failed module. The modules that can communicate will set a DTC indicating the module that cannot communicate.
Conditions for Running the DTCs
- Voltage supplied to the modules is in the normal operating voltage range
- The vehicle power mode requires serial data communication to occur
- DTC U0073 does not have a current status
DTC U0140 Will Set When
- A poor connection at the inoperative module may cause this code to set.
- An improperly powered module may cause this code to set.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | Check for an open or a short to ground or voltage of the low speed GMLAN serial data circuit of the BCM. Did you find and correct the condition? | - | Go to Step 6 | Go to Step 3 |
| 3 | Check for poor connections at the BCM connector. Did you find and correct the condition? | - | Go to Step 6 | Go to Step 4 |
| 4 | - Turn OFF the ignition.
- Disconnect the harness connectors from the BCM.
- Check for the following circuits of the BCM wiring connectors for the indicated condition.
- an open and a short to ground for ignition voltage circuit
- an open for ground circuit
- an open and a short to ground for battery positive circuit
Did you find and correct the condition? | - | Go to Step 6 | Go to Step 5 |
| 5 | - Replace the BCM.
- Perform the BCM reprogramming procedure.
Did you complete the replacement? | - | Go to Step 6 | - |
| 6 | - Install a scan tool.
- Turn ON the ignition.
- Select the Display DTCs function for the BCM.
Does the scan tool display any DTCs which do not begin with a "U"? | - | Go to the related DTC diagnosis | Go to Step 7 |
| 7 | Select the Display DTCs function for the SDM. Does the scan tool display any DTCs which do not begin with a "U"? | - | Go to the related DTC diagnosis | Go to Step 8 |
| 8 | - Use the scan tool in order to clear the DTCs.
- Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared.
Did you complete the action? | - | System OK | - |
Diagnostic Trouble Code (DTC) U0151
Lost Communication With SCM
DTC Descriptors
DTC U0151 00: Lost Communication With Sensing and Diagnostic Module (SDM)
Circuit/System Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The serial data communication enable circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wakeup serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).
Conditions for Running the DTCs
- The vehicle power mode master requires serial data communication to occur.
- The vehicle power mode requires serial data communication to occur
Conditions for Setting the DTC
A supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
The module(s) is never signaled, therefore the specific subsystem(s) will not function.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
- Use the DTC Descriptor list above to determine the module which is not communicating.
- If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
- Use Data Link References to determine if the module uses high or low speed GMLAN serial data communications.
- Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.
- This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is equipped with the option that uses that module.
Circuit/System Testing
- Using the DTC Descriptor and Diagnostic Aids above, determine the module that is not communicating that should be tested.
- Ignition OFF, disconnect the harness connector of the module that is not communicating.
Important : Only the high speed GMLAN modules have a the serial data communication enable circuit OR the accessory wakeup serial data circuit. Refer to the module schematics to identify which modules have these circuits. If the module that is not communicating does not have one of these circuits, proceed to step 4.
- Ignition ON, verify that a test lamp illuminates between the serial data communication enable circuit OR the accessory wakeup serial data circuit and ground.
- If the test lamp does not illuminate, repair the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
- Ignition ON, verify that a test lamp illuminates between all battery positive voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Verify that a test lamp illuminates between all ignition voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Test for less than 1 ohm of resistance between the module ground circuits and ground.
- If greater than 1 ohm, repair the ground circuit for an open.
- Use Data Link References to determine if the non-communicating module should use low speed GMLAN serial data.
- If the module is GMLAN high speed only, replace the module.
- Test for less than 1 ohm of resistance in the low speed GMLAN serial data circuit between the non-communicating module and the module that displays the DTC.
- If greater than 1 ohm of resistance, test the low speed GMLAN serial data circuit for open/high resistance.
- If all circuits test normal, replace the module that is not communicating.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.Control Module References for BCM replacement, setup, and programming. Refer to
Section 9V, Body Control Module.Diagnostic Trouble Code (DTC) U0168
Lost Communication With Vehicle Theft Deterrent (VTD) Control Module
DTC Descriptors
DTC U0168 00: Lost Communication With Vehicle Theft Deterrent (VTD) Control Module
Circuit/System Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The serial data communication enable circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wakeup serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).
Conditions for Running the DTCs
- The system voltage is between 9-16 volts.
- The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
A supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
The module(s) is never signaled, therefore the specific subsystem(s) will not function.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
- Use the DTC Descriptor list above to determine the module which is not communicating.
- If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
- Use Data Link References to determine if the module uses high or low speed GMLAN serial data communications.
- Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.
- This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is equipped with the option that uses that module.
Circuit/System Testing
- Using the DTC Descriptor and Diagnostic Aids above, determine the module that is not communicating that should be tested.
- Ignition OFF, disconnect the harness connector of the module that is not communicating.
Important : Only the high speed GMLAN modules have a the serial data communication enable circuit OR the accessory wakeup serial data circuit. Refer to the module schematics to identify which modules have these circuits. If the module that is not communicating does not have one of these circuits, proceed to step 4.
- Ignition ON, verify that a test lamp illuminates between the serial data communication enable circuit OR the accessory wakeup serial data circuit and ground.
- If the test lamp does not illuminate, repair the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
- Ignition ON, verify that a test lamp illuminates between all battery positive voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Verify that a test lamp illuminates between all ignition voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Test for less than 1 ohm of resistance between the module ground circuits and ground.
- If greater than 1 ohm, repair the ground circuit for an open.
- Use Data Link References to determine if the non-communicating module should use low speed GMLAN serial data.
- If the module is GMLAN high speed only, replace the module.
- Test for less than 1 ohm of resistance in the low speed GMLAN serial data circuit between the non-communicating module and the module that displays the DTC.
- If greater than 1 ohm of resistance, test the low speed GMLAN serial data circuit for open/high resistance.
- If all circuits test normal, replace the module that is not communicating.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Diagnostic Trouble Code (DTC) U0214
Lost Communication With Remote Function Actuation (RFA) Control Module
DTC Descriptors
DTC U0214 00: Lost Communication With Remote Function Actuator (RFA)
Circuit/System Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The serial data communication enable circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wakeup serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).
Conditions for Running the DTCs
- The system voltage is between 9-16 volts.
- The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
A supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
The module(s) is never signaled, therefore the specific subsystem(s) will not function.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
- Use the DTC Descriptor list above to determine the module which is not communicating.
- If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
- Use Data Link References to determine if the module uses high or low speed GMLAN serial data communications.
- Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.
- This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is equipped with the option that uses that module.
Circuit/System Testing
- Using the DTC Descriptor and Diagnostic Aids above, determine the module that is not communicating that should be tested.
- Ignition OFF, disconnect the harness connector of the module that is not communicating.
Important : Only the high speed GMLAN modules have a the serial data communication enable circuit OR the accessory wakeup serial data circuit. Refer to the module schematics to identify which modules have these circuits. If the module that is not communicating does not have one of these circuits, proceed to step 4.
- Ignition ON, verify that a test lamp illuminates between the serial data communication enable circuit OR the accessory wakeup serial data circuit and ground.
- If the test lamp does not illuminate, repair the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
- Ignition ON, verify that a test lamp illuminates between all battery positive voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Verify that a test lamp illuminates between all ignition voltage circuits and ground.
- If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
- Test for less than 1 ohm of resistance between the module ground circuits and ground.
- If greater than 1 ohm, repair the ground circuit for an open.
- Use Data Link References to determine if the non-communicating module should use low speed GMLAN serial data.
- If the module is GMLAN high speed only, replace the module.
- Test for less than 1 ohm of resistance in the low speed GMLAN serial data circuit between the non-communicating module and the module that displays the DTC.
- If greater than 1 ohm of resistance, test the low speed GMLAN serial data circuit for open/high resistance.
- If all circuits test normal, replace the module that is not communicating.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Diagnostic Trouble Code (DTC) B1325
Battery Low/High Voltage
DTC Descriptors
DTC B1325 03: Battery Low Voltage
DTC B1325 07: Battery High Voltage
Circuit Description
The control modules on this vehicle monitor the battery voltage through the battery positive voltage circuits. This vehicle has multiple modules that will set this DTC.
Conditions for Running the DTCs
The voltage supplied to the control modules are in the range of 7-18 volts.
Conditions for Setting the DTC
DTC B1325 03
- The control module detects a system voltage below the calibrated value usually 7.8 volts.
- The above condition is present at least 1 seconds.
DTC B1325 07
- The control module detects a system voltage above the calibrated value usually 18 volts.
- The above condition is present at least 1 seconds.
Action Taken When the DTC Sets
- The control module immediately disables all outputs when an out of range voltage condition has been detected, with the exception of GMLAN and Run/Crank relay that are disabled after a 3 minute delay.
- The setting of other DTCs is inhibited.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Install a scan tool.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Battery Voltage Signal parameter in the data list of the module setting the DTC
Is the Battery Voltage Signal parameter displayed in the specified range? | 9 - 18 V | Go to Step 3 | Go to Step 4 |
| 3 | Is the DTC set as a current DTC? | - | Go to Step 7 | |
| 4 | - Disconnect the harness connector of the module setting the DTC.
- Measure the voltage between the battery positive voltage circuit at the module harness connector and a good ground.
Is the measured value in the specified range? | - | Go to Step 6 | Go to Step 5 |
| 5 | Test the battery positive voltage circuit for the following conditions: - A short to ground
- An open
- A high resistance
Did you find and correct the condition? | - | Go to Step 9 | |
| 6 | Test the all of ground circuits of the module for an open or high resistance. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 7 |
| 7 | Did you find and correct the condition? | - | Go to Step 9 | Go to Step 8 |
| 8 | Replace the affected module Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | - | Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you find and correct the condition? | - | System OK | Go to Step 2 |
Diagnostic Trouble Code (DTC) B0158
OAT(Outside Air Temperature) Sensor Circuit
DTC Descriptors
DTC B0158 0E: OAT Sensor Circuit Below Threshold
DTC B0158 0D: OAT Sensor Circuit Above Threshold
Circuit Description
The control modules on this vehicle monitor the battery voltage through the battery positive voltage circuits. This vehicle has multiple modules that will set this DTC.
Conditions for Running the DTCs
The ignition is turned ACC or RUN
Conditions for Setting the DTC
DTC B0158 0E
- Once the voltage is out of range the code shall remain current until the voltage becomes less than 0.28Ohm for 1sec.
DTC B0158 0D
- Once the voltage is out of range the code shall remain current until the voltage becomes greater than 36.1KOhm for 1sec.
Conditions for Clearing the DTC
- The DTC will become history if the HVAC control module no longer detects the condition that set the DTC.
- A current DTC clears when the malfunction is no longer present.
Circuit/Syste Circuit
The numbers below refer to the step numbers on the diagnostic table.
- This step tests for the proper operation of the circuit in the high voltage range.
- This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Install a scan tool.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Appropriate parameter.
Does the scan tool indicate that the Appropriate parameter is within the specified range? | 0.3 Ω ~ 3.6 K Ω | | Go to Step 3 |
| 3 | - Turn OFF the ignition.
- Disconnect the appropriate outside air temperature sensor.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Appropriate parameter.
Does the scan tool indicate that the Appropriate parameter is greater than the specified value? | 0.3 Ω | Go to Step 4 | Go to Step 5 |
| 4 | - Turn OFF the ignition.
- Connect a 3-amp fused jumper wire between the signal circuit of the appropriate air temperature sensor and the low reference circuit of the appropriate air temperature sensor.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Appropriate parameter.
Does the scan tool indicate that the Appropriate parameter is less than the specified value? | 3.6 K Ω | Go to Step 9 | Go to Step 6 |
| 5 | Test the signal circuit of the appropriate air temperature sensor for a short to ground. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 10 |
| 6 | Test the signal circuit of the appropriate air temperature sensor for a short to voltage, a high resistance, or an open. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 7 |
| 7 | Test the low reference circuit of the appropriate air temperature sensor for a high resistance or an open. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 8 |
| 8 | Test the following signal circuits for a short to voltage: - Ambient air temperature sensor
- Ambient light sensor
Did you find and correct the condition? | - | Go to Step 13 | Go to Step 10 |
| 9 | Did you find and correct the condition? | - | Go to Step 13 | Go to Step 11 |
| 10 | Did you find and correct the condition? | - | Go to Step 13 | Go to Step 12 |
| 11 | Replace the appropriate air temperature sensor. Did you complete the replacement? | - | Go to Step 13 | - |
| 12 | Did you complete the replacement? | - | Go to Step 13 | - |
| 13 | - Use the scan tool in order to clear the DTCs.
- Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset? | - | Go to Step 2 | System OK |
