DTC P0652 or P0653
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection\Initial Inspection and Diagnostic Overview
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/System Description
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
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.
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.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
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/Failure Records data.
Circuit/System Testing
Turn OFF the ignition for 30 seconds or until the ECM powers down.
Disconnect the accelerator pedal position (APP) sensor.
Turn ON the ignition, with engine OFF and measure the voltage from the 5-volt reference circuit of the APP sensor 2 to a good ground with a DMM.
If the voltage measures 4.7-5.2 volts, replace the APP sensor.
With the DMM still connected to the 5-volt reference circuit, disconnect all other components connected to the 5-volt reference 2, one at a time.
If voltage changes when one of the above components is disconnected, replace the component.
Test the 5-volt reference 2 circuits for a short to ground or a short to voltage.
If no problem was found in the 5-volt reference 2 circuit, replace the ECM.
