This bulletin pertains to a condition you may be having.
#04-05-25-007: ABS Warning Light On, Traction Off Warning Light On, DTCs C1223 and C1225 Set (Replace Left Front ABS Wheel Speed Sensor Jumper Harness) - (May 26, 2004)
Some customers may comment that the ABS warning light and/or Traction Off warning light is illuminated. Upon investigation, the technician may find ABS codes (C1223 - C1225) set as intermittent or hard failures.
The cause of this condition may be the front wheel speed sensor jumper harness. The harness may check good with the voltmeter, but will not function correctly when subjected to suspension movement, vibration, and flexing.
Visually inspect the left front ABS wheel speed sensor harness connector. The wires may become unseated from the connector. This is especially important on the left side. If the wiring is faulty, replace the harness using the procedure listed below.
Wire, Wheel Speed Sensor
Parts are currently available from GMSPO.
The two systems are tied together. Here is a brief description ok.
Traction Control System (TCS) (NW7)
When drive wheel slip is noted while the brake is not applied, the EBCM will enter traction control mode.
The EBCM requests the PCM to reduce the amount of torque to the drive wheels via serial data messages. The PCM reduces torque to the drive wheels by retarding spark timing and turning off fuel injectors. The PCM reports the amount torque delivered to the drive wheels via serial data messages.
The IPC illuminates the ABS indicator when the following occurs:
The IPC illuminates the low traction indicator when the following occurs:
The IPC illuminates the traction off indicator when the following occurs: