Trouble Shooting

Before attempting to diagnose vehicle, ensure ABS warning light is functioning properly. Perform trouble shooting procedures on ABS warning light to eliminate unnecessary repairs and/or component replacement.

1. Turn ignition switch from OFF to ON position. Check ABS warning light operation. Ensure ABS warning light illuminates for 2 seconds, then turns off (observe for at least 20 seconds). If ABS warning light illuminates for 2 seconds and goes out, no diagnostic trouble codes are stored and ABS is okay.
2. If ABS warning light flashes, check for the following:
   • Intermittent power to ABS control module.
   • Grounded short connector lead.
   • Faulty ABS control module.
   • Intermittent ABS control module ground.
3. If ABS warning light remains on without flashing, at least one diagnostic trouble code has been stored. Retrieve diagnostic trouble code from ABS control module memory, then diagnose and repair fault. Refer to DIAGNOSIS . If diagnostic trouble code cannot be retrieved, check the following:
   • Grounded short connector lead.
   • ABS control module power supply.
   • Faulty ABS control module.
   • ABS fuse (20-amp).

   If no problems are found with listed components, check pressure differential switch wiring for an open or short. Pressure differential switch is located in proportioning by-pass valve.

4. If ABS warning light does not illuminate at all, check the following:
   • ABS control module harness connector.
   • ABS control module ground.
   • ABS warning light power.
   • ABS warning light fuse (10-amp).
   • ABS warning light bulb and wiring.