P0698

DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LAU)

Diagnostic Instructions

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

DTC Descriptors

DTC P0641
5 V Reference 1 Circuit

DTC P0642
5 V Reference 1 Circuit Low Voltage

DTC P0643
5 V Reference 1 Circuit High Voltage

DTC P0651
5 V Reference 2 Circuit

DTC P0652
5 V Reference 2 Circuit Low Voltage

DTC P0653
5 V Reference 2 Circuit High Voltage

DTC P0697
5 V Reference 3 Circuit

DTC P0698
5 V Reference 3 Circuit Low Voltage

DTC P0699
5 V Reference 3 Circuit High Voltage

Circuit/System Description

The engine control module (ECM) has 3 internal 5 V reference circuits. Each internal reference circuit provides external 5 V reference circuits for more than one sensor. A short to ground or short to voltage on one external 5 V reference circuit can affect all the components connected to the same internal 5 V reference circuit.

Conditions for Running the DTC

- The ignition is ON for greater than 3 s.
- DTCs P0641, P0642, P0643, P0651, P0652, P0653, P0697, P0698, and P0699 run continuously when the above condition is met.

Conditions for Setting the DTC

The 5 V reference circuit voltage is above or below a predetermined threshold for greater than 1 s or for a cumulative of 10 s.

Action Taken When the DTC Sets

DTCs P0641, P0642, P0643, P0651, P0652, P0653, P0697, P0698, and P0699 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0641, P0642, P0643, P0651, P0652, P0653, P0697, P0698, and P0699 are Type A DTCs.

Diagnostic Aids

The 5 V reference 1, 2, and 3 circuits provide 5 V to the following sensors:

P0641, P0642, and P0643

- Economy mode switch
- Turbocharger pressure sensor
- Secondary air injection (AIR) pressure sensor
- Engine oil pressure (EOP) sensor
- Fuel tank pressure sensor

P0651, P0652, and P0653

- All four camshaft position sensors
- Accelerator pedal position (APP) sensor 1

P0697, P0698, and P0699

- Throttle position sensor 1 and 2
- Crankshaft position sensor
- Accelerator pedal position (APP) sensor 2
- A/C Refrigerant Pressure Sensor

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

Connector End View Reference
Component Connector End Views

Electrical Information Reference

- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs

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

Scan Tool Reference
Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, check the diagnostic trouble code (DTC) information with a scan tool. DTC P0641, P0642, P0643, P0651, P0652, P0653, P0697, P0698, or P0699 should not set.
2. Observe the scan tool's status parameter for 5 V reference circuit 1, 2, or 3. 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

1. NOTE: Additional DTCs will set when disconnecting the components.

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.
3. 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.
4. If the voltage is greater than the specified range, test for a short to voltage on the 5 V reference circuit for each of the affected components. If all circuits test normal, replace the K20 ECM.

5. NOTE: A short to voltage on the signal circuit of certain components may cause this DTC to set.

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 Voltage parameter. Verify the voltage remains between 4.8-5.2 V.

6. 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 after completing the diagnostic procedure.

- Accelerator Pedal with Position Sensor Assembly Replacement Service and Repair
- Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LF1) Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LAU)
- 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
- Crankshaft Position Sensor Replacement Service and Repair
- Fuel Injector Replacement
- Fuel Tank Pressure Sensor Replacement Service and Repair
- Secondary Injection Shutoff Valve Pressure Sensor Replacement
- Throttle Body Assembly Replacement Throttle Body Assembly Replacement
- Turbocharger Pressure Sensor Replacement
- Control Module References for ECM replacement, setup, and programming