Internal Control Module Keep Alive Memory (KAM) Error
The POWERSTROKE-P0603 (Power Stroke) diesel fault code means: Internal Control Module Keep Alive Memory (KAM) Error. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- advanced
- Estimated cost
- $50-$900
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Common Symptoms
- CEL
- Erratic idle after battery disconnect
- Lost learned adaptations
Probable Causes (Ranked by Likelihood)
- Weak/dead PCM KAM battery backup Likely
- Intermittent KAM power circuit Likely
- Failed PCM Possible
Step-by-Step Diagnostic Procedure
Check continuity of PCM KAM fuse and battery feed.
Clear codes and drive to relearn. If P0603 returns, PCM repair or replacement is required.
Swollen or weak batteries frequently trigger this on 7.3L trucks.
Frequently Asked Questions
What is P0603 on a 7.3L Power Stroke?
P0603 on a 7.3L Power Stroke (1994-2003) indicates: Internal Control Module Keep Alive Memory (KAM) Error. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.
Can I drive with P0603 on my Power Stroke?
Yes, you can generally drive with this code, but diagnose it soon to prevent further damage.
How much does it cost to fix P0603?
Repair cost is typically $50-$900 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.
P0603 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: