Applicable Systems
OBD-II

Symptoms

ECM/PCM internal processor fault; ECM self-test detected processing error; engine may enter limp mode or not start.

Possible Causes

  • ECM internal processor failure
  • ECM overheating
  • Electrical spike damage to ECM

Troubleshooting Steps

  1. Step 1: Check ECM for physical damage (burn marks, water)
    No physical damage
  2. Step 2: Check all ECM grounds and power
    Grounds < 1 ohm, power stable
  3. Step 3: Attempt ECM reflash
    Reflash may resolve if firmware corruption
  4. Step 4: If reflash fails, replace ECM
    New ECM operates normally
  5. Step 5: Program and verify all systems
    All systems functional

How to Reset

Replace ECM; requires OEM-specific programming tool.

Common Replacement Parts

  • ECM/PCM (OEM spec, requires programming)

Frequently Asked Questions

  • Q: What causes ECM processor failure?

    Voltage spikes (jump start, alternator failure), heat, water intrusion, or manufacturing defects. Always check grounds and battery before condemning ECM.

Related OBD-II Generic (SAE J2012) Fault Codes

Source: SAE J2012 standard DTC list + OBD-II portal

Category: OBD-II