For 1990-2009 cars
ABS Components
Antilock Brake System Schematics

### Circuit Description

The ABS ACTIVE indicator lamp is connected to the IG-COIL METER fuse through CKT 8B01. This circuit is hot in the ON and START ignition switch positions. The EBCM turns ON the ABS ACTIVE by grounding CKT 9W01 and CKT 6C01.

When the ignition switch is turned to the ON position, the EBCM turns ON the ABS ACTIVE indicator for 3 seconds for a bulb check. Whenever the vehicle is involved in an ABS event, the EBCM tuns ON the ABS ACTIVE indicator for the duration of the event (and 1-2 seconds after the event), notifying the driver that ABS is in operation.

### Diagnostic Aids

The following conditions may cause an intermittent malfunction:

• | A poor connection

• | Rubbed-through wire insulation

• | A broken wire inside the insulation

Thoroughly inspect any circuitry that may cause the intermittent complaint 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

• | Open IG-COIL METER fuse

• | Open bulb filament

• | Open CKT 9W01 and/or CKT 6C01

• | Open within I/P gage printed circuit

Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 | Inspect the IG-COIL METER fuse. Is the IG-COIL METER fuse open? | -- | Go to Step 9 | Go to Step 3
3 |

1. Turn the ignition switch to LOCK.
2. Disconnect the EBCM connector C1.
3. Connect a fused jumper wire between the EBCM harness connector C1 terminal D4 and ground.
4. Turn the ignition switch to ON.

Does the ABS ACTIVE indicator light?

--

Go to Step 7

Go to Step 4

4 |

1. Turn the ignition switch to LOCK.
2. Remove and disconnect the I/P gauge cluster.
3. Inspect the ABS ACTIVE indicator lamp filament.

Is the ABS ACTIVE indicator bulb filament open?

--

Go to Step 10

Go to Step 5

5 |

1. Turn the ignition switch to ON.
2. Connect the test lamp between the I/P gauge cluster harness connector C3 terminal 11 and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 11

6 | Using the J 39200 measure resistance between I/P gauge cluster harness connector C3 terminal 6 and the EBCM harness connector C1 terminal D4. Is the resistance within the range specified in the Value(s) column? | 0-2 ohms | Go to Step 13 | Go to Step 12
7 |

1. Turn the ignition switch to LOCK.
2. Reconnect the connector(s).
3. Install the Scan Tool .
4. Turn the ignition switch to ON.
5. Using the Scan Tool , select Special Functions.
6. Select Lamp Test.
7. Turn the ABS ACTIVE indicator lamp ON.

Is the ABS ACTIVE indicator ON?

--

Go to Step 8

Go to Step 14

8 | Using the Scan Tool , toggle the ABS ACTIVE indicator ON and OFF. Did the ABS ACTIVE indicator turn ON and OFF? | -- | Go to Step 16 | Go to Step 15
9 | Replace the IG-COIL METER fuse. Is the repair complete? | -- | Go to Step 17 | --
10 | Replace the ABS ACTIVE indicator bulb. Is the repair complete? | -- | Go to Step 17 | --
11 | Repair the open or high resistance in CKT 8B01 between IG-COIL METER fuse and I/P gauge cluster harness connector C3 terminal 11. Is repair complete? | -- | Go to Step 17 | --
12 | Repair the open or high resistance in CKT 9W01 and/or CKT 6C01 between the I/P harness connector C3 terminal 6 and EBCM connector C1 terminal D4. Is the repair complete? | -- | Go to Step 17 | --
13 | Inspect the I/P gauge cluster printed circuit for cuts or cracks causing an open circuit to the ABS ACTIVE indicator bulb and repair as necessary. Is the repair complete? | -- | Go to Step 17 | --
14 | Inspect the EBCM connector C1 and the I/P gauge cluster harness connectors for possible intermittent poor terminal contact and repair as necessary. Refer to Diagnostic Aids. If no problem is found, replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

--

Go to Step 17

--

15 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to Step 17 | --
16 | Malfunction is not present at this time. Refer to Diagnostic Aids for additional information. Is the action complete? | -- | Go to Step 17 | --
17 |

1. Turn the ignition switch to LOCK.
2. Reconnect the connector(s).
3. Turn the ignition switch to ON and observe the ABS ACTIVE indicator.

Did the ABS ACTIVE indicator light for 3 seconds then turn OFF?

--

System OK

Go to Diagnostic System Check