C1211

CIRCUIT DESCRIPTION
When the ignition is first turned to RUN, the EBCM/EBTCM goes through a self-check which lasts 2-4 seconds.

During this test, the EBCM/EBTCM grounds terminal 34. This energizes the main relay. Once the self-check is completed, the main relay remains energized. This delivers battery voltage to both the EBCM/EBTCM and the BPMV during vehicle operation. The constant voltage supply allows the vehicle to enter ABS mode without delay.

The main relay is de-energized whenever a system malfunction causes the amber ANTILOCK indicator to illuminate. This causes the ABS system to shut down.

CONDITIONS FOR SETTING THE DTC
DTC C1211 sets when the ignition switch is in RUN and battery voltage is not detected at the EBCM/EBTCM terminal 3 and/or 33.

ACTION TAKEN WITH THE DTC SETS
The following actions are taken when the DTC sets:
^ A malfunction DTC is stored
^ The ABS is disabled
^ The ANTILOCK indicator is turned ON

CONDITIONS FOR CLEARING THE DTC
The DTC will be cleared tinder following conditions:
^ Conditions for the malfunction are no longer present. Use the Scan Tool clear DTCs function
^ 100 ignition switch key cycles have passed with no malfunctions detected

DIAGNOSTIC AIDS
The following conditions may cause valve supply voltage interruption:
^ An open fuse
^ An open in any of the following circuits:
^ CKT 242
^ CKT 441
^ CKT 1632
^ CKT 1633
^ A short to ground in any of the following circuits:
^ CKT 242
^ CKT 441
^ CKT 1632
^ CKT 1633
^ A slow reacting or open Main relay

A Main relay that reacts slowly due to a mechanical malfunction may cause an intermittent DTC C1211. If the Diagnostic Table suggests replacing the EBCM/EBTCM, install a new relay and recheck the system before replacing the EBCM/EBTCM.

One of the following conditions may cause intermittent malfunctions:
^ A poor connection
^ Rubbed-through wire insulation
^ A wire that is broken inside the insulation

Inspect any suspect circuitry for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal to wiring connections
^ Physical damage to the wiring harness

TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.
2. This step checks for an open power feed for the solenoids internal to the BPMV.
3. This step ensures that the BPMV is not internally shorted to ground.
12. This step checks the integrity of CKT 1633 to EBCM/EBTCM and the BPMV.

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DTC C1211 VALVE SUPPLY VOLTAGE INTERRUPTION