C1216

DTC C1216: ABS Relay Coil Circuit Open (Part 1 Of 2):

DTC C1216: ABS Relay Coil Circuit Open (Part 2 Of 2):

DTC C1216 Schematic:

Circuit Description
Ignition voltage is supplied to terminal 85 of the ABS relay. The EBCM is then able to energize the pull-in coil by completing the ground circuit at Electronic Brake Control Module (EBCM) terminal A11. 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 the ABS solenoids.

Conditions for Setting the DTC
This DTC will set when the following conditions are met:
^ Voltage in CKT 850 falls below 7.05 volts with an ABS relay coil fault detected (DTC C1214).
^ This DTC may take up to 2 seconds to set because it takes time for the ABS relay voltage to decay.
^ This test detects an open in the ABS relay coil circuit (CKT 879).
^ This DTC can be set anytime.
An open in CKT 879 will not allow the ABS relay to be energized thus preventing power to the EBCM, and from the EBCM to the motors and ABS solenoids.

Action Taken When the DTC Sets
A malfunction DTC is stored, ABS is disabled, and the amber ABS indicator lamp is turned ON. The red BRAKE warning lamp is turned ON if the rear piston in the motor pack is not expected to be in the home position.
Note: DTC C1214 will also set with this DTC. If DTC C1214 is set as current DTC, follow the diagnostic table for this DTC first.

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 (open coil).
^ Open or high resistance in CKT 879.
An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.
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 backed out terminals, improper mating, broken lock, improperly formed or damaged terminals and for poor terminal-to-wire connection before component replacement:
^ EBCM connector C1.
^ Poor ABS relay harness connector terminal contacts.



Test Description
The numbers below refer to step numbers on the diagnostic table.
2. Checks voltage input to the EBCM (CKT 850).
3. Checks ABS relay coil resistance.
4. Checks for an open in CKT 879.
5. Checks for an open in CKT 350A/B/C/D.
6. Confirms if this DTC resets after 2 drive cycles.