PCM - IDM Communication Fault
The POWERSTROKE-P1668 (Power Stroke) diesel fault code means: PCM - IDM Communication Fault. This is a moderate severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- advanced
- Estimated cost
- $300-$1,200
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Common Symptoms
- CEL
- Stalling
Probable Causes (Ranked by Likelihood)
- Damaged communication wire PCM-IDM Likely
- Failed IDM Likely
Step-by-Step Diagnostic Procedure
Check continuity on the IDM comm wires.
Replace IDM.
Frequently Asked Questions
What is P1668 on a 7.3L Power Stroke?
P1668 on a 7.3L Power Stroke (1994-2003) indicates: PCM - IDM Communication Fault. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.
Can I drive with P1668 on my Power Stroke?
No. Stop driving and arrange for towing. Continued operation risks serious engine or emissions system damage.
How much does it cost to fix P1668?
Repair cost is typically $300-$1,200 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.
P1668 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: