For 1990-2009 cars

# Supplement To Bulletin (07-05-25-004) - keywords ABS antilock brake C0035 C0040 C0045 C0050 DTC ESC light message stability TCS traction water

Subject: | Supplement To Bulletin (07-05-25-004)

Models: | 2008 / 09 Chevrolet Malibu

| 2008 / 09 Pontiac G6

| 2008 / 09 Saturn Aura

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

### Condition/Concern:

Some customers may comment about the following conditions

• | Antilock Brake System (ABS) Warning light on

• | Traction Control System (TCS) / Electronic Stability Control (ESC) system Warning light on

• | Service Traction and/or Service ESC message(s) displayed on DIC

The ABS and/or Traction Malf/off and/or Stability Malf/off indicator(s) come on with the occurrence of base DTC's: C0035, C0040, C0045, and/or C0050 set in the EBCM EBTCM. This can be caused by water intrusion into the wheel speed sensor connector at any of the front or rear wheel speed sensor(s). This may lead the Dealer Technician to unnecessarily replacing the EBCM and/or any particular wheel speed sensor/bearing assembly - and/or leaving the vehicle with a high probability it will return for similar concerns later in time.

#### Cause:

The cause of this condition may be water leaking through the wiring harness and filling the wheel speed sensor/bearing assembly connector with water. This conditon could cause shorting of the circuits or terminals rendering the wheel speed sensor/bearing assembly temporarily or permanently inoperable causing the various DTC to set. If water has intruded into the WSS chip packaging, the short condition can and will short the blocking capacitor that is part of the internal WSS circuitry. These types of conditions will not clear once the water has dried. Permanent damage has been done and the WSS Bearing / Assembly must be replaced. Since the non-driven (rear) WSS terminals are insert-molded and the driven (front) are not - this permanent damage scenario is more prevalent on the front WSS.

Suspected water entry points may be at the:

• | 1A) Body-Main to ABS Front Jumper connector

• | 2A) ABS Front Jumper to Front Wheel Speed Sensor pigtail connector

• | 3A) Anywhere in between #1A and #2A via a cut in the circuit's insulation

• | 1B) Body-Main to the ABS Rear Jumper connector.

• | 2B) ABS Rear Jumper to Rear Wheel Speed Sensor direct-connect connector

• | 3B) Anywhere in between #1B and #2B via a cut in the circuit's insulation

#### DTCs Involved:

C0035.xx

C0040.xx

C0045.xx

C0050.xx

Where xx for this issue is usually 00 - but may be also present with 0F or 18.

00 - is the open, short, general electrical malfunction, etc symptom

0F - is the erratic (jitter, dropout) symptom

18 - is the missing / amplitude less than allowed symptom.

### Recommendation/Instructions:

#### Recommendation / Instructions - Front WSS' - C0035 and C0040

1. Unplug the appropriate wheel speed sensor (WSS) connector and inspect the male and female terminals at both locations 1A and 2A (above) looking for evidence of corrosion caused by water intrusion. Corroded terminals on the Front WSS pigtail will need to be replaced once determined that the WSS is operational, or needs to be replaced. Corroded terminals on the ABS Front Jumper harness, and/or Body-Main may need to be replaced pending whether the Front Jumper harness is still acceptable, or needs to be replaced.
2. Check the ABS Front Jumper wiring harness for it's part number / identification label to see if the jumper was manufactured on any of the suspect dates: The Front ABS Jumper harness manufacturing dates in question are: 07NO07, 26NO07, 13DE07, and 17DE07. Jumper harnesses manufactured on these dates may have cut(s) in the WSS circuit's insulation that may or may not be readily visible upon close inspection due to the post-manufacturing process that the front ABS jumper harnesses undergo.
3. If the front ABS jumpers are manufactured within the timeframes described above - or have been visually inspected (special attention paid to the connector ends of the jumper) and have circuit insulation damage - the jumper harness should be replaced and the vehicle retested before the EBCM and/or WSS/Bearing assembly are even considered being replaced.
4. Note that if water had entered the internals of the Front WSS, the capacitor inside the WSS processing chip (all internal and not visible) likely has be permanently damaged and the WSS/Bearing assembly will need to be replaced. The WSS operation needs to be checked prior to replacement - it will either work or not work giving a good indication whether the capacitor was damaged. Also note that the WSS operation is to be checked fully, and not simply via performing a resistance measurement.
5. If the above steps have not aided in resolving the issue, refer back to regular troubleshooting of EBCM and WSS/Bearing assembly.

#### Recommendation / Instructions - Rear WSS' - C0045 and C0050

1. Unplug the appropriate wheel speed sensor (WSS) connector and inspect the male and female terminals at both locations 1B and 2B (above) looking for evidence of corrosion caused by water intrusion. Corroded terminals on the Rear WSS will need to be cleaned as best possible once determined that the WSS is still operational, or needs to be replaced. Corroded terminals on the ABS Rear Jumper harness, and/or Body-Main may need to be replaced pending whether the Rear Jumper harness is still acceptable, or needs to be replaced.
2. If the rear ABS jumpers have been visually inspected (special attention paid to the connector ends of the jumper) and have circuit insulation damage - the jumper harness should be replaced and the vehicle retested before the EBCM and/or WSS/Bearing assembly are even considered being replaced.
3. Note there is a separate PI for the 2008 Pontiac G6 Rear ABS Jumper harness as this has been seen to have a "higher warranty issue than other vehicles".
4. Note the Rear WSS have direct-connect terminals that are insert molded to the WSS/Bearing assembly - meaning water will have a much harder time entering the internals of the Rear WSS, and thus damaging the capacitor inside the WSS processing chip (all internal and not visible). The Rear WSS may simple return to operational capability once dried out. The WSS operation needs to be checked prior to replacement - it will either work or not work giving a good indication whether the capacitor was damaged. Also note that the WSS operation is to be checked fully, and not simply via performing a resistance measurement.
5. If the above steps have not aided in resolving the issue, deter back to regular troubleshooting of EBCM and WSS/Bearing assembly.

Important: After installing software, road test the vehicle and verify that the ESC/TCS and ABS light go off while driving and codes are able to be cleared. If the code test had not passed prior to the last time the ignition was turned off, the code will still be active upon key up and will not clear until it is determined the fault is no longer present. In this case vehicle speed will be required.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.