Normal Operation

The stability/traction control system is controlled by the ABS module. The ABS module continuously monitors and compares the rotational speed of each wheel and when it detects a wheel spinning excessively, modulates brake pressure to the appropriate brake caliper. The ABS module will also send a message to the PCM along the High Speed Controller Area Network (HS-CAN) bus to modulate engine torque by adjusting engine timing and decreasing fuel injector pulses.

The system can be disabled by pressing the stability/traction control switch located in the Front Controls Interface Module (FCIM) or the HVAC module (depending on vehicle options), the switch is hard-wired to the Instrument Cluster (IC). When the stability/traction control switch is pressed, circuit CCA15 (YE/GY) is momentarily connected to the ground circuit GD114 (BK/BU) through the FCIM  or the HVAC module. The IC  detects this ground and sends a signal to the PCM and the ABS module along the HS-CAN  bus to disable the stability/traction control system. The IC  will also illuminate the stability/traction control indicator on the IC  or the message center (if equipped).

Because the stability/traction control switch is grounded through the FCIM  or HVAC, any concerns with those systems should be addressed before  diagnosing the stability/traction control switch.

Certain DTCs being present in the ABS module or communication DTCs are present in the IC  or PCM will disable the system. When the system is disabled due to DTCs being present, both the ABS warning indicator and the stability/traction control indicator will be illuminated.

• DTC P174F:23 Traction Control Enable/Disable Switch Lamp Circuit: Signal Stuck Low - If the stability/traction control switch is pressed and held, or stuck in place for more than 120 seconds or if the switch is pressed at all during the IC  on-demand self test, DTC C1093 will be set.

  This pinpoint test is intended to diagnose the following: 

• Wiring, terminals or connectors
• PCM
• ABS module
• IC 
• Stability/traction control switch (part of the FCIM  or HVAC module)