Ignition Diagnostic Monitor Pulsewidth Not Defined
Findings, check these first
- Aftermarket ignition components confusing the monitor
- Failing ignition module with erratic pulsewidth
- Corrupted PCM calibration
- Wiring fault distorting the IDM signal
- Failing coil pack
Standard procedure
- Return ignition parts to stock for diagnosis
- Check for spark on all cylinders
- Inspect IDM wiring
- Verify PCM calibration level
- Replace the module or coil per signal tests
Code lookup
Type a code above, or start from a symptom or a common code.
Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.
Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1357 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1357: Ignition Diagnostic Monitor Pulsewidth Not Defined
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1357 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1357: Ignition Diagnostic Monitor Pulsewidth Not Defined
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-06.
Report a correction for P1357. Include your vehicle, the issue and a source if you have one.