P0652
DTC P0642, P0643, P0652, or P0653
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 P0642 00
- 5V Reference 1 Circuit Low Voltage
DTC P0643 00
- 5V Reference 1 Circuit High Voltage
DTC P0652 00
- 5V Reference 2 Circuit Low Voltage
DTC P0653 00
- 5V Reference 2 Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) has 2 internal 5 V reference circuits called 5 V reference 1 and 5 V reference 2. Each reference circuit provides 5 V reference circuits for more than one sensor. A fault condition on one 5 V reference circuit will affect the other 5 V reference circuits connected to that reference circuit. The ECM monitors the voltage on the 5 V reference circuits.
The 5 V reference 1 circuit provides 5 V to the following sensors:
* The A/C refrigerant pressure sensor
* The MAP sensor
* The CPP sensor
The 5 V reference 2 provides 5 V to the following sensors:
The crankshaft position sensor
Conditions for Running the DTC
* DTCs P0601 00, P0602 00, P0604 00, P0606 00, P0607 00, and P2610 00 are not set.
* The ignition is in unlock, accessory, run, or crank.
* DTCs P0642 00, P0643 00, P0652 00 and P0653 00 run continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects a voltage out of range condition on the 5 V reference 1 or 2 circuit for more than 0.5 s.
Action Taken When the DTC Sets
DTCs P0642 00, P0643 00, P0652 00, and P0653 00 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0642 00, P0643 00, P0652 00, and P0653 00 are Type A DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics ([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)
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. DTCs P0642 00, P0643 00, P0652 00, and P0653 00 should not set on this ignition cycle.
2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector for the appropriate sensor 5 V reference circuit DTC being diagnosed:
Note: A short to voltage on the signal circuit of certain components may cause this DTC to set.
* 5 V reference 1: B74 Manifold Absolute Pressure Sensor
* 5 V reference 1: B25B Clutch Pedal Position Sensor
* 5 V reference 1: B1 A/C Refrigerant Pressure Sensor
* 5 V reference 1: B150 Fuel Tank Pressure Sensor
* 5 V reference 2: B26 Crankshaft Position Sensor
2. Ignition ON, test for 4.8-5.2 V between each of the 5 V reference circuits and ground at the following component terminals:
* B74 Manifold Absolute Pressure Sensor circuit terminal C (X1)
* B25B Clutch Pedal Position Sensor circuit terminal C (X1)
* B1 A/C Refrigerant Pressure Sensor circuit terminal 2 (X1)
* B150 Fuel Tank Pressure Sensor circuit terminal 3 (X1)
* B26 Crankshaft Position Sensor circuit terminal 3 (X1)
• If the voltage is less than the specified value, test for a short to ground on all the 5 V reference circuits. If all circuits test normal, replace the K20 Engine Control Module.
• If the voltage is greater than the specified value, test for a short to voltage on all the 5 V reference circuits. If all circuits test normal, replace the K20 Engine Control Module.
3. Connect each component associated with the 5 V reference circuit, one at a time, while monitoring the voltage. Verify the voltage remains between 4.8-5.2 V.
• If the voltage display is not within the specified range when a component is connected, test the signal circuit for a short to voltage. If all circuits test normal, replace the appropriate component.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Manifold Absolute Pressure Sensor Replacement (1.8L 2H0 and LUW) (Service and Repair)
* Clutch Pedal Position Sensor Replacement (Service and Repair)
* Crankshaft Position Sensor Replacement (Service and Repair)
* Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for ECM replacement, setup, and programming