Spark

DTC P0641, P0651, or P0697

The engine control module (ECM) has three 5V reference circuits. The ECM provides the 5V reference to various sensors. A short to ground or voltage on one of the 5V reference circuits will affect all components connected to that 5V reference circuit. The ECM monitors the voltage on the 5V reference circuits.

The ECM detects the 5V reference is out of range for 0.06s.

DTC P0641, P0651, and P0697 are Type A DTCs.

DTC P0641, P0651, and P0697 are Type A DTCs.

If a shared 5V reference circuit is shorted to ground or shorted to a voltage, other 5V reference circuits may be affected.

P0641

The 5V reference 1 circuit provides 5V to the following sensors:

P0651

The 5V reference 2 circuit provides 5V to the following sensors:

P0697

The 5V reference 3 circuit provides 5V to the following sensors-- Not used directly for any components.

Schematic Reference

Engine Controls Schematics : Siemens ECM - LPG with LCP → Siemens ECM - Gas without FX3 or LCP → Delphi ECM - FX3

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

1. Ignition ON, observe the DTC information with a scan tool. DTCs P0641, P0651, and P0697 should not set.
2. Engine idling, observe the following circuit status parameters:

•	5V Reference 1 Circuit Status

•	5V Reference 2 Circuit Status

•	5V Reference 3 Circuit Status

⇒	Each parameter should display OK.

3. 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.

Note: Additional DTCs will set when disconnecting components.

1. Ignition OFF, disconnect the harness connector at all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids.
2. Ignition ON, test for 4.8-5.2V between each of the 5V reference circuits listed below and ground:

•	Q38 Throttle Body terminal E

•	B74 Manifold Absolute Pressure Sensor terminal 1

•	B107 Accelerator Pedal Position Sensor terminal 1

•	B107 Accelerator Pedal Position Sensor terminal 6

•	Q14 Exhaust Gas Recirculation (EGR) Valve terminal D

⇒	If less than the specified range, test for a short to ground on the 5V reference circuit. If all circuits test normal, replace the K20 engine control module.

⇒	If greater than the specified range, test for a short to voltage on the 5V reference circuit. 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.

3. Connect each component associated with the 5V reference circuit one at a time while monitoring the scan tool 5V reference circuit status parameter. The parameter should display OK.

⇒	If not the specified value, test the signal circuit of the component for a short to voltage. If the circuit tests normal, replace the component.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.