P0697
DTC P0641, P0651, P0697, or P06A3 (ECM)
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 buses called 5 V reference 1, 5 V reference 2, 5 V reference 3, and 5 V reference 4. Each reference bus provides a 5 V reference for more than one sensor. A short to ground or voltage on one of the 5 V reference circuits can affect all the components connected to that 5 V reference bus. The ECM monitors the voltage on the 5 V reference buses.
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 bus 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 bus provides 5 V to the following components:
* B26 crankshaft position sensor
* S87 economy mode switch
P0697
The 5 V reference 3 bus 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 bus provides 5 V to the following sensors:
* B106 throttle position sensor
* B107 accelerator pedal position sensor 1
• It may be possible to locate the fault by disconnecting one component at a time from the affected 5 V reference bus while viewing the 5 V Reference Circuit Status 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 components have been disconnected from the affected 5 V reference bus and a fault is still indicated, the fault may exist in the wiring harness.
Reference Information
Schematic Reference
Engine Controls Schematics ([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 affected component. 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 each affected component. 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 appropriate scan tool 5 V Reference Voltage parameter. Verify the voltage remains 4.8-5.2 V.
• If not 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 (Service and Repair)
* Throttle Inlet Absolute Pressure Sensor Replacement (Service and Repair)
* 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 (LF1) (Removal and Replacement)
* Crankshaft Position Sensor Replacement (Service and Repair)
* Air Conditioning Refrigerant Pressure Sensor Valve Replacement (LAF) (Service and Repair)Air Conditioning Refrigerant Pressure Sensor Valve Replacement (LF1) (Service and Repair)
* Manifold Absolute Pressure Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for engine control module replacement, setup, and programming