Precision Control System (PCS) Indicator Always On

PCS Indicator Always On





Circuit Description
The PCS On indicator is controlled by the instrument cluster via class 2 serial data messages from the EBCM. When the instrument cluster sees the PCS signal input grounded, it sends a class 2 message to the EBCM that tells the EBCM that the PCS is malfunctioning. The EBCM then disables PCS and TCS and sends a message to the instrument cluster to turn the PCS and TCS indicators ON. Each time the ignition is cycled from OFF to ON, the PCS is enabled.
The following conditions will cause the PCS/TCS indicators to illuminate:
^ The EBCM has disabled the PCS/TCS due to a DTC.
^ The instrument cluster bulbs. check. When the ignition switch is turned to ON, the PCS/TCS indicators will turn on for approximately 3 seconds and then turn OFF.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This test uses the scan tool to check the normal state of the ABS indicator control circuit.
4. This test ensures that the instrument cluster can operate the ABS indicator.