P1356
FordIDM Pulsewidth Indicates Engine Not Turning
The code means the engine control system is receiving IDM pulsewidth information that indicates the engine is not turning. That information is used to assess engine rotation, so a mismatch or missing signal can affect starting or engine operation. The code identifies a detected condition; it does not prove the IDM itself has failed.
⚠️ Before You Begin (Safety First)
If the engine stalls, runs unpredictably, or will not restart, stop somewhere safe and arrange diagnosis rather than continuing to drive. Keep hands and tools clear of moving engine parts during checks.
Common Symptoms
- Crank-no-start or extended cranking if the system cannot establish the expected engine-rotation information.
- Intermittent stalling or difficult restarting if the signal becomes unreliable during operation.
- Rough or inconsistent engine operation may occur if the detected condition affects engine control.
- The vehicle may show no obvious symptom if the condition is intermittent or stored without a current drivability problem.
Common Causes
- An intermittent, damaged, or poorly connected IDM pulsewidth signal circuit.
- A fault in the IDM or its associated wiring, power, or ground.
- Incorrect or missing engine-rotation information from a related input or circuit, causing the system's information to disagree.
- A control-module or connection problem; testing is needed to distinguish this from a wiring or signal fault.
Diagnostic Steps
- Record when the code appeared and note any starting, stalling, or running problems; this helps establish whether the condition is current or intermittent.
- Scan for other codes before clearing anything. Related codes can help separate an IDM signal issue from a broader engine-speed or electrical problem.
- With the engine off, visually inspect accessible relevant wiring and connectors for looseness, corrosion, damage, or rubbing. Do not probe terminals or disconnect components without vehicle-specific instructions.
- If your scan tool supports it, observe engine-speed data while cranking and compare it with the symptoms. A scan-tool reading alone does not identify which component or circuit is at fault.
- If the wiring or signal needs electrical testing, use the correct service information for the exact model, year, and engine, or have a qualified technician perform the tests.
When to Call a Professional
Check all related codes and scan data, including engine-speed information during cranking and IDM-related data if available. Inspect the relevant wiring and connectors, then test the signal and module power and ground using model-, year-, and engine-specific service information. Do not replace the IDM based on this code alone.
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Commonly Asked Questions
Does P1356 prove the IDM needs replacement?
No. The code describes what the IDM pulsewidth information indicates. Wiring, connections, power or ground, related engine-rotation information, and the module itself may need to be checked.
Can the vehicle still run with this code?
It may, depending on whether the condition is current and how it affects engine operation. Starting trouble, stalling, or unpredictable running warrants prompt diagnosis.
What is the IDM pulsewidth information used for?
The system uses this information to assess whether the engine is turning. A signal or interpretation problem can produce this code even when the engine is physically rotating.
Can I diagnose it with a basic code reader?
A basic reader can confirm the code, but diagnosis may require scan data and electrical testing. The available data and correct procedures depend on the vehicle's model, year, and engine.
Browse Available Code Guides
Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.