Trouble Code Diagnosis DTC B1370
DTC Descriptor
DTC B1370 : Device Ignition 1 (ON and START) Circuit Short to Battery
DTC B1370 : Device Ignition 1 (ON and START) Circuit Short to Ground or Open
Circuit Description
This vehicles power mode master (PMM) is the body control module (BCM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determination of the power mode. The PMM receives the ignition switch signals, and additionally a reference voltage signal from the BCM, through the ignition switch, and back to the BCM. There are redundancies within the PMM system that can allow operation of certain subsystems when there are faults in the ignition switch circuits. Other information such as serial data input from other modules and DTCs is also used to determine what power mode signals and information is transmitted by the PMM. The BCM logic uses all this information to identify the operators desired power mode and activate specific discrete signals, and serial data messages for the operation of many different subsystems as necessary. Other modules which have switched voltage inputs may operate in a default mode if the PMM serial data message does not match what the individual module can see from its own connections.The PMM will activate relays and other direct outputs of the PMM as needed according to the calculated power mode. Several relays controlled by the BCM are switched ignition voltage outputs the are pass through circuits within the BCM directly from the ignition switch. If these circuits short to ground, the fuse to the ignition switch will open.
Conditions for Running the DTC
- Ignition switch is in the OFF or ACC positions.
- Ignition switch is in the START position.
Conditions for Setting the DTC
- Ignition 1 voltage circuit is shorted to voltage for more than 2 seconds.
- Ignition 1 voltage circuit is open for more than 2 seconds.
- Ignition 1 voltage, accessory voltage, or off/run/crank voltage circuit shorted to ground.
- Battery positive voltage circuit of the ignition switch open or shorted to ground.
- Run crank relay coil control circuit open (including relay coil and ground).
Conditions for Clearing the MIL/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.
Diagnostic Aids
- A short to ground in the accessory wakeup serial data circuit will cause an open fuse to the ignition switch. DTC U1814 should be current.
- A short to ground in the run/crank ignition 1 voltage circuit of the run crank relay will cause an open fuse to the ignition switch. DTC B1428 should be current.
- The power modes and controls are determined using BCM logic. Comparing the Body Control Module Power Mode data display parameters listed in Circuit/System Verification will determine if there is a power mode fault.
Circuit/System Testing
- Inspect the Ignition Switch fuse for open. The fuse should be OK.
- If the fuse is open, test the following circuits for a short to ground, if all circuits test OK, replace the BCM.
- - Battery positive voltage of the ignition switch
- - Accessory voltage
- - Off/Run crank voltage
- - Ignition 1 voltage
- Disconnect the ignition switch connector.
- Test for battery positive voltage between the battery positive voltage circuit of the ignition switch and ground.
- If less than battery positive voltage, repair the circuit for an open/high resistance
- Perform the ignition switch component test.
- If the ignition switch fails, replace the ignition switch.
- Ignition OFF, disconnect BCM connector C1, test for less than 1.0 volt between the following circuits of the BCM and ground.
- Ignition key out, test for less than 1.0 volt between the following circuits of the BCM and ground.
- - Ignition key resistor signal
- - Off/Run crank
- - Accessory voltage
- - Ignition 1 voltage
- If more than 1.0 volt, repair the circuit for a short to voltage.
- Test for less than 1.0 ohm of resistance between the BCM and the ignition switch on the following circuits.
- - Ignition key resistor signal
- - Off/Run crank
- - Accessory voltage
- - Ignition 1 voltage
- If greater than 5 ohms, repair the circuit for open/high resistance
- Test for infinite resistance between the ignition key resistor signal circuit of the BCM and ground.
- If less than infinite resistance, repair the signal circuit for a short to ground.
- Replace the BCM.
Trouble Code Diagnosis DTC B1380
DTC Descriptor
DTC B1380 : Device Ignition ACCESSORY Circuit Short to Battery
DTC B1380 : Device Ignition ACCESSORY Circuit Short to Ground or Open
Circuit Description
This vehicles power mode master (PMM) is the body control module (BCM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determination of the power mode. The PMM receives the ignition switch signals, and additionally a reference voltage signal from the BCM, through the ignition switch, and back to the BCM. There are redundancies within the PMM system that can allow operation of certain subsystems when there are faults in the ignition switch circuits. Other information such as serial data input from other modules and DTCs is also used to determine what power mode signals and information is transmitted by the PMM. The BCM logic uses all this information to identify the operators desired power mode and activate specific discrete signals, and serial data messages for the operation of many different subsystems as necessary. Other modules which have switched voltage inputs may operate in a default mode if the PMM serial data message does not match what the individual module can see from its own connections.The PMM will activate relays and other direct outputs of the PMM as needed according to the calculated power mode. Several relays controlled by the BCM are switched ignition voltage outputs the are pass through circuits within the BCM directly from the ignition switch. If these circuits short to ground, the fuse to the ignition switch will open.
Conditions for Running the DTC
- Ignition switch is in the START position.
- Ignition switch is in the RUN position.
Conditions for Setting the DTC
- Accessory voltage circuit is shorted to voltage for more than 2 seconds.
- Accessory voltage circuit is open for more than 2 seconds.
- Ignition 1 voltage, accessory voltage, or off/run/crank voltage circuit shorted to ground.
- Battery positive voltage circuit of the ignition switch open or shorted to ground.
Conditions for Clearing the MIL/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.
Diagnostic Aids
- A short to ground in the accessory wakeup serial data circuit will cause an open fuse to the ignition switch. DTC U1814 should be current.
- A short to ground in the run/crank ignition 1 voltage circuit of the run crank relay will cause an open fuse to the ignition switch. DTC B1428 should be current.
- The power modes and controls are determined using BCM logic. Comparing the Body Control Module Power Mode data display parameters listed in Circuit/System Verification will determine if there is a power mode fault.
Circuit/System Testing
- Inspect the Ignition Switch fuse for open. The fuse should be OK.
- If the fuse is open, test the following circuits for a short to ground, if all circuits test OK, replace the BCM.
- - Battery positive voltage of the ignition switch
- - Accessory voltage
- - Off/Run crank voltage
- - Ignition 1 voltage
- Disconnect the ignition switch connector.
- Test for battery positive voltage between the battery positive voltage circuit of the ignition switch and ground.
- If less than battery positive voltage, repair the circuit for an open/high resistance
- Perform the ignition switch component test.
- If the ignition switch fails, replace the ignition switch.
- Ignition OFF, disconnect BCM connector C1, test for less than 1.0 volt between the following circuits of the BCM and ground.
- Ignition key out, test for less than 1.0 volt between the following circuits of the BCM and ground.
- - Ignition key resistor signal
- - Off/Run crank
- - Accessory voltage
- - Ignition 1 voltage
- If more than 1.0 volt, repair the circuit for a short to voltage.
- Test for less than 1.0 ohm of resistance between the BCM and the ignition switch on the following circuits.
- - Ignition key resistor signal
- - Off/Run crank
- - Accessory voltage
- - Ignition 1 voltage
- If greater than 5 ohms, repair the circuit for open/high resistance
- Test for infinite resistance between the ignition key resistor signal circuit of the BCM and ground.
- If less than infinite resistance, repair the signal circuit for a short to ground.
- Replace the BCM.
Trouble Code Diagnosis DTC B1395
DTC Descriptor
DTC B1395 : Voltage Below Threshold
DTC B1395 : Voltage Above Threshold
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
I/P Dimming Voltage Reference | Voltage Below Threshold | Voltage Below Threshold | Voltage Above Threshold | Voltage Below Threshold |
I/P Dimming Control Circuit | B3600 | B3600 | 1 | B3600 |
1. Interior Backlighting Inoperative |
Circuit/System Description
Voltage for the interior backlighting components is supplied from the body control module (BCM). The BCM applies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimming switch, which is part of the headlamp switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the interior lamp dimming switch through the I/P dimming control circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamps supply voltage circuit and they dim to the correct level.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
B1395 : Voltage Below Threshold
The BCM detects a voltage that is lower than 9 volts on the I/P dimming voltage reference circuit.
B1395 : Voltage Above Threshold
The BCM detects a voltage that is greater than 12 volts on I/P dimming voltage reference circuit.
B3600
The BCM detects a voltage that is lower than 5 volts on the I/P dimming control circuit.
Action Taken When the DTC Sets
The I/P lamps are not illuminated.
Conditions for Clearing the DTC
The BCM clears this code from current when the fault is removed from the system.
Circuit/System Verification
Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then I/P Fuse Blockome full bright.
Circuit/System Testing
- Clear the DTC. Disconnect the mirror control switch(dimmer control).
- Connect a DMM between the I/P dimming voltage reference circuit and the negative terminal of the battery.
- Ignition ON, test for 9-14 volts.
- If less than 9 volts, test the I/P dimming voltage reference circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the BCM.
- If greater than 14 volts test the I/P dimming voltage reference circuit for a short to voltage. If the circuit/connections test normal, replace the BCM.
- If the voltage is correct and all circuits/connections test normal, replace the mirror control switch(dimmer control).
Repair Instructions
Important : Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Mirror control switch(dimmer control) Replacement
- Control Module References for BCM replacement and programming
Trouble Code Diagnosis DTC B1428
DTC Descriptor
DTC B1428 : Ignition Switched Power Relay 1 Circuit
Circuit Description
The body control module (BCM) controls the IGN MAIN PCB relay through the run/crank relay coil control circuit by applying voltage to the circuit. The IGN MAIN PCB relay is energized when the ignition switch is in ON or START, or when a remote start is requested.
Conditions for Running the DTC
- The system voltage is between 9-16 volts.
- The DTC can only run when the output is activated.
Conditions for Setting the DTC
- The DTC will set only when the output is activated and there is a short to ground in the run/crank relay coil control circuit.
Action Taken When the DTC Sets
- The module output driver will be shut down and not supply voltage to the run/crank relay coil control circuit.
Conditions for Clearing the DTC
- The current DTC will clear when the module request for the output is removed or 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 DMM MIN/MAX function to capture/locate intermittent conditions.
- Short to voltage in the run/crank relay coil control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF.
Circuit/System Testing
- Ignition OFF, disconnect the IGN MAIN PCB relay and connect a test lamp between the relay control circuit and ground.
- Cycle the ignition ON and OFF. The test lamp should turn ON and OFF when changing ignition switch positions.
- If the test lamp remains OFF all the time, test for a short to ground or an open/high resistance on the relay control circuit. If the circuit tests normal, replace the BCM.
- If the test lamp remains ON all the time, test for a short to voltage on the relay control circuit. If the circuit tests normal, replace the BCM.
- If test lamp turns ON and OFF normal, test or replace the IGN MAIN PCB relay.
Trouble Code Diagnosis DTC B1433
DTC Descriptor
DTC B1433 : Ignition Switched Power Relay 2 Circuit
Circuit Description
The body control module (BCM) controls the RUN relay through the run relay coil control circuit by applying voltage to the coil side of the relay. The RUN relay is energized when any of the following conditions are true :
- Ignition Switch is in ACC or RUN.
- The vehicle was remote started.
- The vehicle is in retained accessory power (RAP) mode.
Conditions for Running the DTC
- The system voltage is between 9-16 volts.
- The DTC can only set when the output is actively being requested by the module.
Conditions for Setting the DTC
- The DTC will set only when the module requests the output and there is a short to ground in the run relay coil control circuit.
Action Taken When the DTC Sets
- The module output driver will be shut down and not supply voltage to the circuit.
Conditions for Clearing the DTC
- The current DTC will clear when the module request for the output is removed or 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 DMM MIN/MAX function to capture/locate intermittent conditions.
- Short to voltage in the run/crank relay coil control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF.
Circuit/System Testing
- With the ignition OFF, disconnect the RUN relay and connect a test lamp between the run relay coil control circuit and battery positive voltage. The test lamp should not illuminate.
- If the test lamp illuminates, test for a short to ground on the run relay coil control circuit. If the circuit tests normal and the DTC is current, replace the BCM.
- If the circuit tests normal and the DTC is current, test or replace the RUN relay or BCM.
Trouble Code Diagnosis DTC B1440
DTC Descriptor
DTC B1440 : Power Mode Master Input Circuits Mismatch
Circuit Description
The body control module (BCM) monitors the ignition inputs ignition off/run/crank voltage, ignition 1 voltage and the accessory voltage signals supplied from the ignition switch. The ignition key resistor signal circuit provides 5-volt reference from the BCM to the ignition switch. The BCM uses the sequence that the signals appear, their voltage levels, the engine run flag (ERF) status and the remote start status to determine the power mode.
Conditions for Running the DTC
- Ignition switch is in the RUN position.
Conditions for Setting the DTC
- BCM senses an open or short to voltage on the off/run/crank voltage circuit when both ignition accessory/run and ignition run/crank parameters are active.
- BCM senses an open on the battery positive voltage circuit while engine is running. An open on the battery voltage circuit can be caused by a short to ground on any of the following circuits :
- - Battery positive voltage
- - Accessory voltage
- - Ignition 1 voltage
- - Off/run/crank voltage
Action Taken When the DTC Sets
- The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the GMLAN serial data communications circuits.
- The other modules on the vehicle operate in a fail-safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the GMLAN serial data communications circuits.
- The vehicle may not start.
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 DMM MIN/MAX function to capture/locate intermittent conditions.
Circuit/System Testing
- With the ignition OFF, disconnect the BCM connector.
- With the ignition OFF w/key out and in the ACC positions, measure for 0 volts between the off/run/crank voltage circuit at the BCM connector and ground.
- If over 0 volts, disconnect the ignition switch and check the off/run/crank voltage circuit for short to voltage or short to other ignition switch signal circuit.
- With the ignition OFF w/key in, measure for battery voltage between the off/run/crank voltage circuit at the BCM connector and ground.
- If less than battery voltage, disconnect the ignition switch and check the off/run/crank voltage circuit for an open or short to ground.
- With the ignition in the RUN and START positions, measure for battery voltage between the ignition 1 voltage circuit at the BCM connector and ground.
- If less than battery voltage, disconnect the ignition switch and check the ignition 1 voltage and battery positive voltage circuits for an open or short to ground.
- With the ignition in the ACC and RUN positions, measure for battery voltage between the accessory voltage circuit at the BCM connector and ground.
- If less than battery voltage, disconnect the ignition switch and check the ignition voltage and battery positive voltage circuits for an open or short to ground.
Trouble Code Diagnosis DTC B1441
DTC Descriptor
DTC B1441 : Device Ignition OFF, RUN, and Crank Circuit Short to Battery
DTC B1441 : Device Ignition OFF, RUN, and Crank Circuit Short to Ground or Open
Circuit Description
The body control module (BCM) monitors the ignition inputs ignition off/run/crank voltage, ignition 1 voltage and the accessory voltage signals supplied from the ignition switch. The ignition key resistor signal circuit provides 5-volt reference from the BCM to the ignition switch. The BCM uses the sequence that the signals appear, their voltage levels, the engine run flag (ERF) status and the remote start status to determine the power mode.
Conditions for Running the DTC
- Ignition switch is in the START position.
Conditions for Setting the DTC
- Off/run/crank voltage circuit is shorted to voltage for more than 2 seconds.
- Off/run/crank voltage circuit is open for more than 2 seconds.
Action Taken When the DTC Sets
- The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the GMLAN serial data communications circuits.
- The other modules on the vehicle operate in a fail-safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the GMLAN serial data communications circuits.
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 DMM MIN/MAX function to capture/locate intermittent conditions.
Circuit/System Testing
- With the key out of ignition and with the key in ACC, measure for infinite resistance between the battery positive voltage and the off/run/crank voltage terminals of the ignition switch. Repeat the same measurement between the ignition key resistor signal and the off/run/crank voltage terminals of the ignition switch.
- If less than infinite ohms, replace the ignition switch.
- With the key in ignition, in OFF position, measure for less than 1 ohm between the battery positive voltage and the off/run/crank voltage terminals at the ignition switch.
- If over 1 ohm, replace the ignition switch.
- With the key in the RUN position, measure for less than 1 ohm between the ignition key resistor signal and the off/run/crank voltage terminals at the ignition switch.
- If over 1 ohm, replace the ignition switch.
- With the key in the START position, measure for 1170-1430 ohms between the ignition key resistor signal and the ignition off/run/crank terminals at the ignition switch.
- If out of range, replace the ignition switch.
Trouble Code Diagnosis DTC B1475
DTC Descriptor
DTC B1475 :Retained Accessory Power Circuit
Circuit Description
The body control module (BCM) controls the retained accessory power (RAP) relay through the RAP relay control circuit by applying voltage to the coil side of the relay. The RAP relay is energized when any of the following conditions are true :
- Ignition Switch is in ACC or RUN.
- The vehicle was remote started.
- The vehicle is in retained accessory power (RAP) mode.
Conditions for Running the DTC
- The system voltage is between 9-16 volts.
- The DTC can only run when the output is actively being requested by the module.
Conditions for Setting the DTC
- The DTC will set only when the module requests the output and there is a short to ground in the RAP relay control circuit.
Action Taken When the DTC Sets
- The module output driver will be shut down and not supply voltage to the circuit.
Conditions for Clearing the DTC
- The current DTC will clear when the module request for the output is removed or 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 DMM MIN/MAX function to capture/locate intermittent conditions.
- The radio RAP mode is separate function and will still operate properly.
- The ignition switch will not return to the OFF position if the RAP relay does not energize.
Circuit/System Testing
- Disconnect the RAP relay and connect a test lamp between the RAP relay control circuit and ground.
- Ignition ON. The test lamp should turn ON.
- If the test lamp remains OFF, test for a short to ground the relay control circuit. If the circuit tests normal, replace the BCM.
- If the test lamp turns ON, test or replace the RAP relay.
Trouble Code Diagnosis DTC B1480
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1480 Battery Rundown Protection Circuit
Circuit Description
The body control module (BCM) supplies battery positive voltage to the courtesy lamps, instrument panel (I/P) compartment lamp, console lamp and both visor vanity mirror lamps. In the event that any of these lamps were to remain illuminated for more than several minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power courtesy lamps supply voltage circuit to prevent a total battery discharge condition.
Conditions for Running the DTC
- The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
DTC B1480
The inadvertent power courtesy lamps supply voltage circuit to the courtesy lamps, I/P compartment lamp, console lamp and both visor vanity mirror lamps is shorted to ground for longer than 1 second.
Action Taken When the DTC Sets
The courtesy lamps, I/P compartment lamp, console lamp and both visor vanity mirror lamps will not operate.
Conditions for Clearing the DTC
- This DTC will clear on current status after the condition for setting the fault is corrected.
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- History and current DTCs can be cleared using a scan tool.
Diagnostic Aids
Perform a visual inspection for loose or poor connections at all related components.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | |
| 2 | - Install a scan tool.
- Turn ON the ignition.
Is DTC B1480 present? | - | Go to Step 3 | Test for Intermittent Conditions and Poor Connections |
| 3 | Test the inadvertent power courtesy lamps supply voltage circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 5 | Go to Step 4 |
| 4 | Replace the body control module (BCM). Refer to Control Module References for replacement and programming. Did you complete the replacement? | - | Go to Step 5 | - |
| 5 | - 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 |
Trouble Code Diagnosis DTC B1517
DTC Descriptor
This diagnostic procedure supports the following DTC :
DTC B1517 Battery Voltage
This vehicle has DTCs which include DTC symptoms
DTC Symptom Descriptor |
Voltage Below Threshold |
Voltage Above Threshold |
Circuit Description
The body control module (BCM) has designated circuits for monitoring vehicle system voltage. The BCM monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range. The BCM monitors the system voltage over an extended length of time. If the BCM detects the system voltage is outside an expected range for the calibrated length of time, or the BCM battery sense circuits differ by 2 volts DTC B1517 will set. Other modules also monitor system voltage the system voltage message is sent to the other modules and will default to 12.9 volts.
Conditions for Running the DTC
This DTC shall run only if the BCM has power, ground, and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.
Conditions for Setting the DTC
- The battery voltage falls below 11 volts, engine speed greater than 1,100 RPM for 15 seconds.
- The battery voltage is greater 16 volts, engine speed greater than 1,100 RPM for 15 seconds.
- The battery voltage differs by 2 volts on the BCM battery sense circuits for 10 seconds.
Action Taken When the DTC Sets
B1517
The Battery indicator turn ON.
B1517
The Battery indicator turn ON.
Conditions for Clearing the DTC
- The DTC will clear current status when the fault is no longer present.
- A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
- Use the scan tool Clear DTC function to clear the DTC.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- This step tests for the proper voltage at battery positive voltage sense circuits of the BCM. If voltages are not within the proper operating range, the voltage sense circuits needs to be tested.
- This step tests the ground sense circuit of the BCM.
- This step tests for the proper voltage of the battery sense circuits to the BCM. If voltage is not within the proper operating range, the battery positive voltage and ground circuits of the BCM need to be tested.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | |
| 2 | - Install a scan tool.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Battery Voltage parameters in the body control module (BCM) data list.
Do any of the voltages differ more than the specified value? | 2 V | Go to Step 5 | Go to Step 3 |
| 3 | - Turn OFF the ignition.
- Disconnect the BCM harness connectors.
- Turn ON the ignition, with the engine OFF.
- Measure the voltage between the battery positive voltage circuits of the BCM and the ground circuits of the BCM.
Do the voltages differ more than the specified value? | 2 V | Go to Step 9 | Go to Step 4 |
| 4 | Measure the voltage from the battery positive voltage circuits of the BCM and a good ground. Do the voltages differ more than the specified value? | 2 V | Go to Step 8 | Go to Step 7 |
| 5 | - Turn ON the ignition.
- Measure the voltage between the battery positive voltage circuits of the BCM and the ground circuits of the BCM.
Does the voltage measure within the specified range? | 10.5 - 15.5 V | Go to Step 9 | Go to Step 6 |
| 6 | Measure the voltage between the battery positive voltage circuits of BCM and a good ground. Does the voltage measure within the specified range? | 10.5 - 15.5 V | Go to Step 8 | Go to Step 7 |
| 7 | Test the battery positive voltage circuits of BCM for a high resistance or an open. Did you find and correct the condition? | - | Go to Step 11 | Go to Step 9 |
| 8 | Test the ground circuits of the BCM for a high resistance or an open. Did you find and correct the condition? | - | Go to Step 11 | Go to Step 9 |
| 9 | Inspect for poor connections at the harness connector of the BCM. Did you find and correct the condition? | - | Go to Step 11 | Go to Step 10 |
| 10 | Replace the module BCM. Refer to Control Module References for replacement and programming. Did you complete the replacement? | - | Go to Step 11 | - |
| 11 | - 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 |
 | |  | |
| © Copyright Chevrolet Europe. All rights reserved |
