DTC P0652 or P0653. Chevrolet Express

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2008 🢒 Express - AWD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0652 or P0653

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 P0652: 5 Volt Reference 2 Circuit Low Voltage

DTC P0653: 5 Volt Reference 2 Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
APP Sensor 2 - 5-Volt Reference	P0117, P0462, P0522, P0652, P011A, P2454	P2138	P2127	P0118, P0653, P011A, P244B, P2455	--
Oil Pressure Sensor - 5-Volt Reference	P0117, P0462, P0522, P0652, P011A, P2454	P0522	P0522	P0118, P0522, P0653, P011A, P244B, P2455	--
Fuel Rail Pressure Sensor - 5-Volt Reference	P0117, P0462, P0522, P0652, P011A, P2454	P0087, P0192	P0193	P0118, P0653, P011A, P2455	--
DPF Differential Pressure Sensor	P0117, P0462, P0652, P011A, P2454	P2453, P244B	P2454	P0118, P0653, P011A, P2455	--

The engine control module (ECM) supplies 5 volts to components through 5-volt reference circuits. These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together in three reference groups inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect multiple components. The ECM monitors voltage on the 5-volt reference circuits.

Conditions for Running the DTC

•	The ignition is ON.

•	The diagnostics run continuously.

Conditions for Setting the DTC

DTC P0652

•	The ECM detects the 5-volt reference 2 circuit voltage is less than 4.7 volts.

•	The above condition is present for 2 seconds.

DTC P0653

•	The ECM detects the 5-volt reference 2 circuit voltage is more than 5.2 volts.

•	The above condition is present for 2 seconds.

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

•	The engine starts and runs.

•	Observe the 5-Volt Reference 2 Circuit Status parameter with a scan tool. The parameter should display OK.

•	Engine running, observe the DTC information with a scan tool. DTCs P0652 or P0653 should not set.

•	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 Records data.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Accelerator Pedal Position Sensor Replacement

•	Exhaust Pressure Differential Sensor Replacement

•	Engine Oil Pressure Sensor and/or Switch Replacement

•	Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement

•	Control Module References for ECM replacement, setup, and programming.