C1218

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Circuit Description
Ignition voltage is supplied to terminal 85 of the electronic brake control relay. The EBCM is then able to energize the pull-in coil by completing the ground circuit at Electronic Brake Control Module (EBCM) connector C1 terminal D6.The magnetic field created closes the relay contacts and allows battery voltage and current to be supplied to the EBCM. In addition, the EBCM supplies power to the motors and the Antilock Brake System (ABS) solenoids.

Conditions for Setting the Diagnostic Trouble Code (DTC)
- DTC C1218 can set after the EBCM commands the Electronic Brake Control Relay ON.
- This test monitors the availability of voltage to the EBCM.
- DTC C1286 is set with DTC C1218 if the rear channel is not expected to be in the home position.

Action Taken When the DTC Sets
- A malfunction DTC stores.
- The ABS disables.
- The ABS warning indicator turns ON.

Conditions for Clearing the DTC
- The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
- 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

Diagnostic Aids
- Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
- Clear the DTCs after completing the diagnosis.
- Test drive the vehicle for three drive cycles in order to verify that the DTC does not reset. Use the following procedure in order to complete one drive cycle:
1. Start the vehicle.
2. Drive the vehicle over 16 km/h (10 mph).
3. Stop the vehicle.
4. Turn the ignition to the OFF position.

The following list contains items that need to be inspected when diagnosing this system:
- Short to voltage in Circuit (CKT) 9X01.
- Malfunctioning electronic brake control relay (low or no coil resistance).

IMPORTANT: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.