DTC C0625. Buick Lucerne 2009

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2009 🢒 Lucerne 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC C0625

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 Descriptor

DTC C0625 08: Left Rear Position Sensor Circuit Signal Invalid

The automatic level control (ALC) position sensor provides a signal voltage between 0.5-4.85 volts to the ALC module. This signal voltage represents the wheel's position relative to the body. The ALC module provides a 5-volt reference and a low reference to the sensor.

Conditions for Running the DTC

•	Ignition voltage is between 9-16 volts.

•	Vehicle is in motion.

Conditions for Setting the DTC

•	The ALC module detects the voltage at the position sensor signal circuit is less than 0.5 volt or greater than 4.75 volts for more than 500 milliseconds.

•	The ALC module detects that there is a wide variation of the signal voltage over a predetermined period of time.

Action Taken When the DTC Sets

ALC functionality is suspended.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists.

Reference Information

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

Verify that DTC C0625 is not set.

⇒	If the DTC is set, perform the Suspension Position Calibration procedure. If the DTC resets replace the ALC sensor/module.

Repair Instructions

Control Module References for automatic level control sensor/module replacement, setup, and programming

Repair Verification

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Use the scan tool Diagnostic Counter Reset output control function to bypass the 3 consecutive ignition cycle requirement for setting a DTC. This will ensure that if a DTC was to be reset during the repair verification process, it will be displayed on the scan tool.
Turn OFF the ignition for 60 seconds.
Turn ON the ignition.
If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the and perform the appropriate diagnostic procedure.