Alternator Warning Lamp Illuminated in Instrument Cluster, DTC P0625 Set (Clean Terminals)

This bulletin has been reissued following determination that the condition described below may also result (in V6 engined vehicles only) from the conservative Regulated Voltage Control calibration described in bulletin H07-08-08.

Customers may comment that the alternator warning lamp is displayed in the instrument cluster and the battery light is illuminated. Technicians may find DTC P0625 (alternator F terminal low voltage) set.

DTC P0625 sets when the F terminal duty cycle drops below 4.98% for more than 15 seconds. Investigations have identified that fretting corrosion in the X1 connector pins 1 and 2 on the alternator to be the major cause of P0625 setting. Fretting corrosion causes high resistance in the circuit which leads to an open circuit condition. The corrosion is aggravated by high temperatures and normal engine vibration.

It has also been determined that this DTC may occur as a result of the calibration applied to the Regulated Voltage Control. The conservative strategy which was adopted in favor of minimizing engine loading during battery charging, has been found in some instances to prevent full battery charge. This revised calibration is included in TIS CD 2007/04 and later.

After confirming that this DTC is set and that the alternator is charging correctly, perform the following procedure.

1. Disconnect alternator harness connector X1.
2. Check the terminal retention and condition of connector X1.
3. Clean the terminals in the X1 connector wiring harness and the alternator connector with terminal contact cleaner.
4. Apply Nyogel grease to the terminals in the wiring harness connector.

Notice: Failure to clean the pins properly or work the Nyogel grease into the terminals can lead to repeat failure.

5. Reconnect the wiring harness connector and then disconnect again. Repeat this three times to ensure Nyogel grease is thoroughly worked into the terminals and connector
6. Reprogram the Regulated Voltage control.

SPS Programming New RVC calibration

Important: Prior to programming, ensure that the battery is fully charged.

Perform Service Programming (SPS) of the Body Control Module (BCM) from TIS2WEB or TIS DVD 2007/04 or later.

After SPS Programming

After SPS programming has been completed, it will be necessary to relearn both the brake position sensor and the SDM primary key to the BCM.

This can be done by selecting the following on the Tech 2®:

Select "Brake pedal position sensor learn" and follow the Tech 2® prompts.

After this has completed, select "Program SDM primary key to BCM" and follow the Tech 2® prompts.

After programming has completed. perform a vehicle wide DTC check and clear all DTCs.

If the vehicle is equipped with Rear Seat Entertainment (RSE), remove the RSE fuse (fuse 1) in the trunk compartment fuse box for 30 seconds.

For vehicles repaired under warranty, use: