Diagnostic Trouble Code Diagnostics Inoperative

CAUTION: If Anti-Lock Brake System/Traction Control Electronic Control Unit (ABS/TRAC ECU) replacement is necessary during testing, always ensure ABS/TRAC ECU connectors and ground circuit are okay. If either is suspect, repair and repeat testing to confirm ABS/TRAC ECU malfunction.

Check ABS warning light circuit. See ABS WARNING LIGHT CIRCUIT under SYSTEM TESTS. Check TRAC OFF warning light circuit. See TRAC OFF WARNING LIGHT (TRAC CUT SWITCH CIRCUIT) under SYSTEM TESTS. Check Tc terminal circuit. See Tc TERMINAL CIRCUIT under SYSTEM TESTS. If all preceding tests are okay, replace ABS/TRAC ECU.