P06A3
DTC P0641, P0651, P0697, or P06A3 (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 5 V reference circuits. The ECM provides the 5 V reference to various sensors. Each reference circuit provides a 5 V reference for more than one sensor. An open, short to ground, or short voltage on one of the 5 V reference circuits can affect all the components connected to that 5 V reference circuit. The ECM monitors the voltage on the 5 V reference circuits.
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
P0641
The 5 V reference 1 circuit provides 5 V to the following sensors:
* B150 fuel tank pressure (FTP) sensor
* B17 barometric pressure (BARO) sensor, throttle inlet absolute pressure sensor
* B47B fuel rail pressure (FRP) sensor
* B1 A/C refrigerant pressure sensor
* All four B23 camshaft position sensors
P0651
The 5 V reference 2 circuit provides 5 V to the B26 crankshaft position sensor.
P0697
The 5 V reference 3 circuit provides 5 V to the following sensors:
* B74 manifold absolute pressure (MAP) sensor
* B107 accelerator pedal position sensor 2
P06A3
The 5 V reference 4 circuit provides 5 V to the following sensors:
* B106 throttle position sensor
* B107 accelerator pedal position sensor 1
• If the condition is intermittent, move the related harnesses and connectors with the engine operating. Monitor the scan tool 5 V Reference Circuit Test Status parameters for the affected components. The Circuit Test Status parameter will change from OK or Not Run to Fault if there is a condition with the circuit or a connection.
Reference Information
Schematic Reference
Engine Controls Schematics (LAU) ([1][2]Electrical Diagrams)Engine Controls Schematics (LF1) ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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 or Not Run.
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 each of the affected 5 V reference circuits and ground.
• If the voltage is less than the specified range, test for a short to ground or for an open between the ECM and the affected circuit splice. If the circuit tests 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. If the circuit tests 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 appropriate scan tool 5 V Reference Circuit Status parameter. The parameter should continue to display OK.
• If the parameter displays Fault 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 (Service and Repair)
* Throttle Inlet Absolute Pressure Sensor Replacement (LF1) (Service and Repair)
* Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail (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 with Position Sensor Assembly Replacement (Accelerator Pedal with Position Sensor Assembly Replacement)
* Throttle Body Assembly Replacement (LF1) (Removal and Replacement)Throttle Body Assembly Replacement (LAU) (Removal and Replacement)
* Crankshaft Position Sensor Replacement (Service and Repair)
* Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LF1) (Service and Repair)Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LAU) (Service and Repair)
* Manifold Absolute Pressure Sensor Replacement (LF1) (Service and Repair)
* Control Module References (Programming and Relearning)for engine control module replacement, setup, and programming