DTC P0641-P0643, P0651-P0653, or P0697-P0699. Chevrolet HHR 2009

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2009 🢒 HHR 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 DTC P0641-P0643, P0651-P0653, or P0697-P0699

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 P0641: 5-Volt Reference 1 Circuit

DTC P0642: 5-Volt Reference 1 Low Voltage

DTC P0643: 5-Volt Reference 1 High Voltage

DTC P0651: 5-Volt Reference 2 Circuit

DTC P0652: 5-Volt Reference 2 Low Voltage

DTC P0653: 5-Volt Reference 2 High Voltage

DTC P0697: 5-Volt Reference 3 Circuit

DTC P0698: 5-Volt Reference 3 Low Voltage

DTC P0699: 5-Volt Reference 3 High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Accelerator Pedal Position (APP) Sensor 1 5-Volt Reference 2 Circuit	P0652	P2122	P0653
Accelerator Pedal Position (APP) Sensor 2 5-Volt Reference 3 Circuit	P0698	P2127	P0699
Air Conditioning (A/C) Refrigerant Pressure Sensor 5-Volt Reference 3 Circuit	P0698	P0532	P0699
Crankshaft Position Sensor 5-Volt Reference 3 Circuit	P0698	P0335	P0699
Engine Oil Pressure Sensor 5-Volt Reference 3 Circuit	P0698	P0520	P0699
Exhaust Camshaft Position Sensor 1 5-Volt Reference 2 Circuit	P0652	P0368	P0653
Fuel Rail Pressure Sensor 5-Volt Reference 1 Circuit	P0642	P0192	P0643
Fuel Tank Pressure (FTP) Sensor 5-Volt Reference 1 Circuit	P0642	P0452	P0643
Intake Camshaft Position Sensor 1 5-Volt Reference 2 Circuit	P0652	P0343	P0653
Manifold Absolute Pressure (MAP) Sensor 5-Volt Reference 1 Circuit	P0642	P0107	P0643
Throttle Position (TP) Sensor 1 5-Volt Reference 3 Circuit	P0698	P0122	P0699
Throttle Position (TP) Sensor 2 5-Volt Reference 3 Circuit	P0698	P0222	P0699
Intake Air Pressure and Temperature Sensor 5-Volt Reference 1 Circuit	P0642	P0238	P0643

Circuit/System Description

The engine control module (ECM) has 3 internal 5-volt reference busses called 5-volt reference 1, 5-volt reference 2, and 5-volt reference 3. Each reference bus provides 5-volt reference circuits for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference bus. The ECM monitors the voltage on the 5-volt reference busses.

The 5-volt reference 1 bus provides 5 volts to the following sensors:

•	The manifold absolute pressure (MAP) sensor

•	The clutch apply sensor

•	The fuel rail sensor

•	The fuel tank pressure (FTP) sensor

•	The intake air pressure and temperature sensor

The 5-volt reference 2 bus provides 5 volts to the following sensors:

•	The accelerator pedal position (APP) sensor 1

•	The exhaust camshaft position (CMP) sensor

•	The intake camshaft position (CMP) sensor

The 5-volt reference 3 bus provides 5 volts to the following sensors:

•	The APP sensor 2

•	The crankshaft position (CKP) sensor

•	The air conditioning (A/C) refrigerant pressure sensor

•	The throttle position (TP) sensor 1 and 2

•	The brake booster vacuum sensor

Conditions for Running the DTC

•	DTCs P0601, P0602, P0603, P0604, and P0606 are not set.

•	The ignition is in Run, or Crank.

•	The ignition voltage is more than 5.23 volts.

•	DTCs P0641, P0642, P0643, P0651, P0652, P0653, P0697, P0698, and P0699 run continuously when the above conditions are met.

Conditions for Setting the DTC

P0641, P0651, and P0697

These DTCs set when the ECM detects a voltage out of tolerance condition on the 5-volt reference 1, 2 or 3 bus for more than 3 seconds.

P0642, P0652, and P0698

These DTCs set when the ECM detects a low voltage condition on the 5-volt reference 1, 2, or 3 bus for more than 3 seconds.

P0643, P0653, and P0699

These DTCs set when the ECM detects a high voltage condition on the 5-volt reference 1, 2, or 3 bus for more than 3 seconds.

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

•	It may be possible to locate the fault by disconnecting one component at a time from the 5-volt reference circuit while viewing the 5-Volt Reference circuit parameter on the scan tool. The scan tool parameter would change from Fault to OK when the source of the fault is disconnected.

•	If all 5-volt 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

With the ignition ON and the engine OFF, observe the 5-volt Reference 1, 2, and 3 parameters. The scan tool should display OK for a normally operating system.

Circuit/System Testing

Important: Additional DTCs will set when disconnecting the components.

Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC.

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

Ignition ON, measure for 4.8-5.2 volts between one of the 5-volt reference circuits and ground.

⇒	If the voltage is less than the specified range, test for a short to ground on all the 5-volt reference circuits. If all circuits test normal, replace the ECM.

⇒	If the voltage is greater than the specified range, test for a short to voltage on all the 5-volt reference circuits. If all circuits test normal, replace the ECM.

Connect each component associated with the 5-volt reference circuit, one at a time, while monitoring the voltage. The voltage should not change more than 1 volt.

⇒	If the voltage display increases greater than the specified value when a component is connected, test the signal circuit for a short to voltage. If all circuits test normal, replace the ECM.

⇒	If the voltage display decreases more than the specified value when a component is connected, replace the component.

Repair Instructions

•	Accelerator Pedal Position Sensor Replacement

•	Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement

•	Crankshaft Position Sensor Replacement

•	Camshaft Position Sensor Replacement - Exhaust

•	Camshaft Position Sensor Replacement - Intake

•	Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement

•	Fuel Tank Pressure Sensor Replacement

•	Intake Air Pressure and Temperature Sensor Replacement

•	Manifold Absolute Pressure Sensor Replacement

•	Throttle Body Assembly Replacement

•	Diagnostic Trouble Code (DTC) List - Vehicle for ECM replacement, setup, and programming.

Repair Verification

With the ignition ON and the engine OFF, observe the 5-Volt Reference 1, 2 and 3 parameters. The scan tool should display 5-volt reference circuit status OK for a normally operating system.