If a malfunction occurs, the system will identify the problem and the computer will assign and store a fault code for the fault(s). The dashboard warning lamp will be illuminated to inform the driver that a fault has been found.
During diagnostics, the system will transmit the stored code(s) by flashing the dashboard warning lamp. If two or more codes are stored, they will be displayed from lowest number to highest, regardless of the order of occurrence. The system does not display the diagnostic codes while the vehicle is running.Visual Inspection
Before diagnosing an apparent rear anti-lock problem, make absolutely certain that the normal braking system and power steering systems are in correct working order. Many common problems (dragging parking brake, seepage, etc.) will affect the ABS system. A visual check of specific system components may reveal problems creating an apparent ABS malfunction. Performing this inspection may reveal a simple failure, thus eliminating extended diagnostic time.
See Figure 1
- Turn the ignition switch OFF . Check battery condition; approximately 12 volts is required to operate the system.
- Turn the ignition switch ON and check that the ABS dashboard warning lamp comes on for 3 seconds. If the lamp does not come on, repair the fuse, bulb or wiring.
- Use a jumper wire to attach terminals Tc and E1 of the Data Link Connector (DLC1). This is not the service connector. Turn the ignition ON .
- If a fault code has been set, the dashboard warning lamp will begin to blink 4 seconds later. The number of flashes corresponds to the first digit of a 2-digit code; after a 1.5 second pause, the second digit is transmitted. If a second code is stored, it will be displayed after a 2.5 second pause. Once all codes have been displayed, the entire series will repeat after a 4 second pause. If no codes have been stored, the warning lamp will flash continuously every 1 / 2 second with no variation.
- Turn the ignition switch OFF .
- Check or repair the system as indicated by the fault code.
- After repairs are completed, clear the codes from the memory. If the battery is disconnected during repairs, the controller memory will be erased of all stored codes.
- Remove the jumper wire if one was used and reattach the service connector at the actuator.
- Detach the service connector at the actuator.
- Use the jumper wire to connect terminals Tc and E1 of the Data Link Connector (DLC1). Turn the ignition ON .
- Clear the diagnostic trouble codes stored in the ECU by depressing the brake pedal 8 or more times within 3 seconds.
- After the rapid pedal application, the dash warning lamp should display constant flashing, indicating a normal system. If codes are still displayed, make certain the repairs made to the system are correct. Also inspect the brake light switch at the brake pedal for any binding or sticking.
- Once the codes are cleared, disconnect the jumper wire. The dash warning lamp should go out.