LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Impala Base, 3.8 K >> Repair and Diagnosis >> External Pages >> Different car >> Section 20 (Anti-Lock Brake System With Traction Control System - BOSCH 5.3) >> Diagnostic Tests >> DTC C0121: Valve Relay Circuit Malfunction >> Diagnosis

DTC C0121: Valve Relay Circuit Malfunction: Diagnosis

WARNING: This page is about a different car, the 2001 Pontiac Grand Prix, 2001 Pontiac Firebird, 2001 Oldsmobile Intrigue, and 2001 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform DIAGNOSTIC SYSTEM CHECK  under DIAGNOSIS & TESTING. Go to next step.
  2. Install scan tool. Turn ignition on, engine off. Using scan tool, clear DTCs. If DTC resets, go to next step. If DTC does not reset, see DIAGNOSTIC AIDS  .
  3. Disconnect EBCM connector. Install Universal Pinout Box (J 39700) using Cable Adapter (J 39700-25) to EBCM harness connector only. Check battery voltage circuit (universal pinout box terminals No. 13 and 14) for open, high resistance, or short to ground. If problem was found, repair as necessary. After repair, go to step  5 . If problem was not found, go to next step.
  4. Replace EBCM. See ELECTRONIC BRAKE CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs, go to next step.
  5. Using scan tool, clear DTCs. Operate vehicle. If DTC does not reset, system is okay.
scientia non olet · About LEMON Manuals