P06A3

DTC P0641, P0651, P0697, or P06A3 (ECM, LF1)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0641
- 5 V Reference 1 Circuit

DTC P0651
- 5 V Reference 2 Circuit

DTC P0697
- 5 V Reference 3 Circuit

DTC P06A3
- 5 V Reference 4 Circuit

Circuit/System Description

The engine control module (ECM) has 4 internal 5 V reference circuits. Each internal reference circuit provides a 5 V reference to more than one sensor. Therefore, a short to ground or short to voltage on one external 5 V reference circuit will affect the other components connected to the same internal reference circuit.

Conditions for Running the DTC

DTCs P0641, P0651, P0697, P06A3 run continuously when the ignition is ON.

Conditions for Setting the DTC

The 5 V reference circuit voltage is greater or less than a predetermined threshold.

Action Taken When the DTC Sets

DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs.

Diagnostic Aids

DTC P0641

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

* Fuel tank pressure (FTP) sensor
* Barometric pressure (BARO) sensor, throttle inlet absolute pressure sensor
* Fuel rail pressure (FRP) sensor
* A/C refrigerant pressure sensor
* All four camshaft position sensors

DTC P0651

The 5 V reference 2 circuit provides 5 V to the crankshaft position sensor.

DTC P0697

The 5 V reference 3 circuit provides 5 V to the following sensors:

* Manifold absolute pressure (MAP) sensor
* Accelerator pedal position sensor 2

DTC P06A3

The 5 V reference 4 circuit provides 5 V to the following sensors:

* Throttle position sensor
* Accelerator pedal position sensor 1

It may be possible to locate the fault by disconnecting one component at a time from the 5 V reference circuit while viewing the 5 V Reference Circuit parameter on the scan tool. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected.

If all 5 V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.

Reference Information
Schematic Reference

Engine Controls Schematics (LLT) ([1][2]Electrical Diagrams)Engine Controls Schematics (LF1) ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. DTC P0641, P0651, P0697, or P06A3 should not set.
2. Observe the appropriate scan tool 5 V Reference Circuit Test Status parameter. The 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.

Circuit/System Testing

Note: Additional DTCs will set when disconnecting the components.

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

• If the voltage is less than the specified range, test for a short to ground on the 5 V reference circuit for each of the affected components. If all circuits test normal, replace the K20 ECM.
• If the voltage is greater than the specified range, test for a short to voltage on the 5 V reference circuit for all of the affected components. If all circuits test normal, replace the K20 ECM.

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 affected 5 V reference circuit one at a time while monitoring the voltage. Verify the voltage remains 4.8-5.2 V.

• If not within the specified range when a component is connected, test the signal circuit of that component for a short to voltage. If the circuit tests normal, replace the component.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Fuel Tank Pressure Sensor Replacement (NT7) (Fuel Tank Pressure Sensor Replacement (NT7))Fuel Tank Pressure Sensor Replacement (NU6) (Fuel Tank Pressure Sensor Replacement (NU6))
* Barometric Pressure Sensor Replacement (LF1) ()
* Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (LLT) (Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail)Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (LF1) (Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail)
* Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake (Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake)
* Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust (Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust)
* Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake (Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake)
* Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust (Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust)
* Accelerator Pedal Position Sensor Replacement (Service and Repair)
* Throttle Body Assembly Replacement (LLT) (Removal and Replacement)Throttle Body Assembly Replacement (LF1) (Removal and Replacement)
* Crankshaft Position Sensor Replacement (Service and Repair)
* Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (Service and Repair)
* Manifold Absolute Pressure Sensor Replacement (LF1) ()
* Control Module References (Programming and Relearning) for engine control module replacement, setup, and programming