C1215

EBCM/ABS Relay Schematic:

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

CONDITIONS FOR SETTING THE DTC
This Diagnostic Trouble Code (DTC) will set when the following conditions are met:
^ Voltage in the switched battery input circuit to the EBCM is greater than 7.05 volts after ABS relay is de-energized (CKT 9B01).
^ This DTC can be set anytime after the ABS relay is turned OFF (ABS relay is turned OFF when the ABS is disabled and during bulb check).

NOTE: This test determines if the ABS relay is energized when it should not be. This malfunction would not allow the ABS relay to remove power to the ABS system. If a second malfunction were to occur that would require the ABS relay to be turned OFF, that malfunction will not disable the ABS.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored. ABS is not disabled, and the amber ABS indicator lamp will remain OFF.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
The following list contains items that need to be inspected when diagnosing this system:
^ Faulty ABS relay (contacts closed all the time).
^ Faulty electrical circuit (short to voltage in switched battery input circuit) between the ABS relay and the EBCM (CKT 9B01).

NOTE: The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics.

Inspect The Following Harness Connectors For - improperly formed or damaged terminals before component replacement:
^ EBCM connectors C1 and C2.
^ ABS relay harness connector terminals.

DTC C1215 ABS Relay Contact Circuit Always Active:

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
[3] Checks voltage input to the EBCM (CKT 9B01).
[4] Checks for closed ABS relay terminals.
[5] Checks for short to voltage in CKT 9B01.
[6] Confirms if this DTC resets after 2 drive cycles.