P06D1 — Internal Control Module Ignition Coil Control Performance
An internal self-test in the control module reports a fault in its processing of the "ignition coil control" value. The module computes and cross-checks this value redundantly inside its own processor; when the results disagree, the code sets. It points to a hardware or software fault inside the module itself, not to a defect of the external sensor. Causes are an internal processor or memory fault, corrupted control-module software, or low or disturbed module supply voltage.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Ecu internal processing
- Ignition coils
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Internal software anomaly
Possible symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.