DTC C121 Chevrolet
Engine Control Module or Powertrain Control Module Main Processor Malfunction
Engine Control Module or Powertrain Control Module Main Processor Malfunction
Description
Ignition switch is ON position. No surveillance pulse signals should be input for 0.5 second.
Cause and Solution
MFI relay failed. Shorted MFI relay circuit or connector damage. Open or shorted ignition switch-IG circuit, harness damage or connector damage.
Video Guide
Diagnostic Info
- DTC Code: C121
- Brand: Chevrolet