DTC P0641, P0651, or P0697
Diagnostic Instructions
DTC Descriptors
DTC P0641 03: 5V Reference 1 Circuit Low Voltage
DTC P0641 07: 5V Reference 1 Circuit High Voltage
DTC P0651 03: 5V Reference 2 Circuit Low Voltage
DTC P0651 07: 5V Reference 2 Circuit High Voltage
DTC P0697 03: 5V Reference 3 Circuit Low Voltage
DTC P0697 07: 5V Reference 3 Circuit High Voltage
Circuit/System Description
The engine control module (ECM) has 3 5-volt reference circuits. The ECM provides the 5-volt reference to various sensors. Each reference circuit provides a 5-volt reference for greater than one sensor. A short to ground or voltage on one of the 5-volt reference circuits will affect all components connected to that 5-volt reference circuit. The ECM monitors the voltage on the 5-volt reference circuits.
Conditions for Running the DTC
• | The DTCs run continuously when the above condition is met. |
Conditions for Setting the DTC
The control module detects a voltage above 5.5 V, or below 4.5 V, on any of the 5-volt reference circuits for greater than 0.5 s.
Action Taken When the DTC Sets
• | DTCs P0641, P0651, and P0697 are Type B DTCs. |
• | The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode. |
Conditions for Clearing the DTC
DTCs P0641, P0651, and P0697 are Type B DTCs.
Diagnostic Aids
• | If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected. |
• | The scan tool 5-volt reference circuit status parameter should display OK. |
P0641
The 5-volt reference 1 circuit provides 5 V to the accelerator pedal position (APP) sensor 1
P0651, P0652, P0653
The 5-volt reference 2 circuit provides 5 V to the following sensors:
• | The accelerator pedal position (APP) sensor 2 |
• | The fuel rail pressure sensor |
• | The turbocharger boost pressure sensor |
P0697
The 5-volt reference 3 circuit provides 5 V to the following sensors:
• | The air conditioning (A/C) refrigerant pressure sensor |
• | The water in fuel sensor |
• | The diesel particulate filter (DPF) pressure sensor |
Reference Information
Schematic Reference
Engine Controls Schematics : LLW
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. DTCs P0641, P0651, and P0697 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Note: Additional DTCs will set when disconnecting the components.
- Ignition OFF, disconnect the harness connector at all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids.
- Ignition ON, test for 4.6-5.4 V between one of the 5-volt reference circuits and ground.
⇒ | If the voltage is less than the specified range, test the 5-volt reference circuit for a short to ground. If all circuits test normal, replace the K20 Engine Control Module. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for each component associated with the appropriate 5-volt reference circuit for a short to voltage. If all circuits test normal, replace the K20 Engine Control Module. |
Note: A short to voltage on the signal circuit of certain components may cause this DTC to set.
- Connect each component associated with the 5-volt reference circuit one at a time while monitoring the scan tool 5 V reference circuit status parameter. The scan tool parameter should not display Fault.
⇒ | If the scan tool displays Fault when a component is connected, test the signal circuit for a short to voltage. If all circuits test normal, replace the component. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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