For 1990-2009 cars
ABS Components
Cell 44: Buick Indicators
Cell 44: Pontiac Indicators
Cell 44: Oldsmobile Indicators
Cell 10: IGN SW Fuse (1 of 2)
Cell 10: PCM Fuse
Cell 14: G202
Handling ESD Sensitive Parts Notice

### Circuit Description

The ABS Indicator driver circuit runs from the Instrument Panel Cluster (IPC) through the brake lamp driver module to the EBCM/EBTCM. The IPC supplies voltage to the ABS indicator. The EBCM/EBTCM controls the ABS indicator through the brake lamp driver module. The brake lamp driver module acts as an inverter; when the EBCM/EBTCM supplies a ground for the brake lamp driver module, the indicator remains off. When the EBCM/EBTCM removes the ground for the brake lamp driver module, the indicator turns on by using the ground at the brake lamp driver module terminal D.

### Conditions for Setting the DTC

EBCM/EBTCM commands the ABS indicator on and either an open, a short to ground, or a short to voltage is detected in CKT 852.

### Action Taken When the DTC Sets

The DTC is stored, but the ABS is not disabled.

### Conditions for Clearing the MIL/DTC

• | The condition for DTC is no longer present and the scan tool clear DTC function is used.

• | 50 ignition cycles have passed with no DTCs detected.

### Diagnostic Aids

Perform a thorough inspection of the wiring and connectors. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. This step checks if CKT 852 is shorted to voltage.

2. This step checks if CKT 852 is shorted to ground.

3. This step checks for an open in CKT 852.

#### DTC C1211 ABS Indicator Lamp Circuit Malfunction

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the EBCM/EBTCM.
3. Connect the J 39700 universal pinout box using the J 39700-25 cable adapter to the EBCM/EBTCM harness connector only.
4. Disconnect the brake lamp driver module.
5. Turn the ignition switch to the RUN position. Do not start the engine.
6. Using the J 39200 DMM, measure the voltage at terminal 13 of the J 39700 .

Is the voltage within the specified range?

Battery Voltage

Go to Step 3

Go to Step 4

3 | Repair CKT 852 for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
4 |

1. Turn the ignition switch to the OFF position.
2. Using the J 39200 DMM, measure the resistance between terminal 13 and B of the J 39700 .

Is the resistance equal to the specified value?

OL (infinite)

Go to Step 6

Go to Step 5

5 | Repair CKT 852 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
6 |

1. Connect a fused jumper wire between terminals 13 and B of the J 39700 .
2. Using the J 39200 DMM, measure the resistance between the brake lamp driver module harness connector terminal C and a good ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 7

Go to Step 8

7 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
8 | Repair an open or high resistance in CKT 852. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --