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 inventor. When the EBCM/EBTCM supplies a ground for the Brake Lamp Driver Module the ABS indicator remains Off. When the EBCM/EBTCM removes the ground for the Brake Lamp Driver Module the ABS indicator turns On by using the ground at the Brake Lamp Driver Module terminal D.

### 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.

• | In order for the ABS indicator to come On, there must be battery voltage at terminal B of the Brake Lamp Driver Module and a good ground at terminal D of the Brake Lamp Driver Module.

• | If the ABS indicator does not come On and there are no DTCs, then the cause may be one of the following:

• | A malfunctioning Brake Lamp Driver Module

• | CKT 875 is open

• | No power or ground for the Brake Lamp Driver Module

• | A malfunctioning IPC

• | A damaged ABS indicator bulb

• | The EBCM/EBTM sets a DTC when CKT 852 is open, shorted to ground, or shorted to voltage

• | More than one indicator bulb will be inoperative if the battery feed to the IPC indicators is open

### Test Description

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

1. This step checks if the EBCM/EBTCM is not capable of removing the ground for CKT 852

2. This step checks for a short to ground in CKT 39.

3. This step checks for voltage at brake lamp driver module.

4. This step checks for voltage from IPC.

5. This step checks if brake lamp driver module has a good ground.

#### ABS Indicator Inoperative with No DTC Set

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. Turn the ignition switch to the RUN position. Do not start the engine.

Does the ABS indicator turn on?

--

Go to Step 16

Go to Step 3

3 |

1. Turn the ignition switch to the OFF position.
2. Reconnect the EBCM/EBTCM.
3. Check the CHIME fuse D1 in the IP fuse block.

Is the fuse OK?

--

Go to Step 4

Go to Step 5

4 |

1. Install the fuse, if removed.
2. Turn the ignition switch to the RUN position. Don't start the engine.
3. Using the J 39200 DMM, check the voltage at the fuse test terminals.

Is the voltage within the specified range?

Battery Voltage

Go to Step 6

Go to Wiring Repairs in Wiring Systems

5 |

1. Turn the ignition switch to the OFF position.
2. Remove the CHIME fuse D1.
3. Disconnect the brake lamp driver module.
4. Using the J 39200 DMM, measure the resistance between terminal B of the brake lamp driver module harness connector and a good ground.

Is the resistance equal to the specified value?

OL (infinite)

Go to Step 9

Go to Step 8

6 |

1. Turn the ignition switch to the OFF position.
2. Disconnect brake lamp driver module connector.
3. Turn the ignition switch to the RUN position. Do not start the engine.
4. Using the J 39200 DMM, measure the voltage at terminal B of the brake lamp driver module harness connector.

Is the voltage within the specified range?

Battery Voltage

Go to Step 7

Go to Step 17

7 | Using J 39200 DMM, measure the voltage from terminal E of the brake lamp driver module harness connector to a good ground. Is the voltage within the specified range? | Battery Voltage | Go to Step 10 | Go to Step 11
8 | Repair CKT 39 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
9 |

1. Replace the fuse.
2. Reconnect the brake lamp driver module.
3. Turn the ignition switch to the RUN position. Do not start the engine.
4. Recheck the CHIME fuse D1 in the IP fuse block.

Is the fuse OK?

--

Go to Diagnostic System Check

Go to Step 12

10 |

1. Turn the ignition switch to the OFF position.
2. Using the J 39200 DMM, measure the resistance between terminal D of the brake lamp driver module harness connector and a good ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 12

Go to Step 13

11 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the IPC connector C1.
3. Connect a fused jumper wire between CKT 875 of the IPC harness connector and a good ground.
4. Using the J 39200 DMM, measure the resistance between the brake lamp driver module harness connector terminal E and a good ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 14

Go to Step 15

12 | Replace the brake lamp driver module. Refer to Lamp Driver Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
13 | Repair CKT 1250 for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
14 | Suspect the IPC. Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Is the diagnosis complete? | -- | Go to Diagnostic System Check | --
15 | Repair an open or high resistance in CKT 875. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
16 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
17 | Repair an open or high resistance in CKT 39. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --