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 bulb check. When the ignition switch is turned to ON, the PCS/TCS indicators will turn on for approximately 3 seconds and then turn OFF. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
2 | Inspect the EBCM ground, making sure the ground is clear and torqued to the proper specification. Refer to Testing for Intermittent Conditions and Poor Connections and Testing for Short to Ground in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 3 |
3 | With a scan tool, observe the PCS Warning Indicator parameter in the ABS/TCS/PCS/VSES data list. Does the scan tool display Off? | Go to Step 4 | Go to Step 5 |
4 |
Does the PCS indicator illuminate during the bulb check and then turn OFF? | Go to Step 5 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the EBCM. Refer to and in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the instrument cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the EBCM. Refer to Did you complete the repair? | Go to Step 9 | - |
8 | Replace the instrument cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console. Did you complete the replacement? | Go to Step 9 | -- |
9 | Operate the system in order to verify the repair. Did you complete the repair? | System OK | Go to Step 2 |
