POWERSTROKE-P0603 moderate Power Stroke ›

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.

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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

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.

Mechanics Guide Step-by-step diagnosis

Step-by-Step Diagnostic Procedure

  1. Check continuity of PCM KAM fuse and battery feed.

  2. Clear codes and drive to relearn. If P0603 returns, PCM repair or replacement is required.

  3. Swollen or weak batteries frequently trigger this on 7.3L trucks.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines P0603 as a generic OBD-II code)

P0603 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Gas / Automotive (OBD-II) Generic OBD-II definition for P0603 Duramax serious Internal Control Module Keep Alive Memory Error

Commonly Affected Vehicles

  • 1994.5-1997 Ford F-250/F-350 7.3L Power Stroke
  • 1999-2003 Ford F-250/F-350 Super Duty 7.3L Power Stroke
  • 1999-2003 Ford F-450/F-550 Super Duty 7.3L Power Stroke
  • 1994.5-2003 Ford E-350/E-450 7.3L Power Stroke
  • 2000-2003 Ford Excursion 7.3L Power Stroke

Related Codes

P0562P0606

Explore More

More Power Stroke codes → Diesel home All diesel codes Heavy-duty Guides

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