For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Handling ESD Sensitive Parts Notice

### Circuit Description

If DTC C1291 or DTC C1292 failed during the last ignition cycle, DTC C1293 becomes a current failure during the next ignition cycle. DTC C1291 and DTC C1292 will remain in history. DTC C1293 failure keeps ABS disabled until identifying a brake switch ON state.

### Conditions for Setting the DTC

DTC C1293 alone indicates DTC C1291 or C1292 occurred previously, but is intermittent.

### Action Taken When the DTC Sets

• | A malfunction DTC stores.

• | ABS is disabled until the EBCM receives a valid input from the brake switch.

• | The ABS warning indicator turns ON.

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.

### Diagnostic Aids

Use the Data List of the Scan Tool verify proper brake switch operation. The Data List should display the brake switch status change as the brake is applied within 25 mm (1.0 inch) of brake pedal travel.

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

1. Install a Scan Tool .
2. Use the Scan Tool to read the DTCs.

Is DTC C1291 or DTC C1292 set as either a current and/or a history DTC?

--

Go to DTC C1291 Open Brake Lamp Switch Contacts During Deceleration or DTC C1292 Open Brake Lamp Switch When ABS Was Required

Go to Step 3

3 |

1. Select DTC history on the Scan Tool .
2. Verify that the malfunction frequency was infrequent.
3. Use the Scan Tool in order to clear the DTCs.

Did DTC C1293 clear?

--

Go to Diagnostic System Check - ABS

Go to Step 4

4 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check - ABS | --