Basic Diagnostic Procedure

Antilock Brake/Traction Control System diagnosis consists of four basic steps:
1. ABS/TCS Visual Inspection
2. ABS/TCS Functional Check
3. Test Driving Complaint Vehicles
4. Intermittents And Poor Connections

Start all diagnosis with the "ABS/TCS Visual Inspection". Proceed to the "ABS/TCS Functional Check" when the condition is not resolved by the visual inspection. ABS/TCS Visual Inspection

Finish all diagnosis by repeating "ABS/TCS Functional Check" to ensure correct diagnosis. ABS/TCS Functional Check

Some diagnostic procedures require the ignition switch to remain in the RUN position for extended time periods while tests are performed. Low battery voltage may result, causing erroneous voltage readings.

When vehicle system voltage becomes low, it is advisable to connect a battery charger to the vehicle's electrical system and apply a slow charge while testing.

IMPORTANT: When vehicle is equipped with traction control, any symptom which lights the ANTILOCK indicator also lights the TRACTION OFF indicator. Therefore, when both indicators are lit, follow ANTILOCK indicator diagnosis when no diagnostic trouble codes are set.