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P0603

Internal Control Module Keep Alive Memory Error

The ECM's keep-alive memory (KAM), which stores learned values like fuel trims, has failed.

SeverityCritical
CategoryElectrical
Est. Repair Cost$300-$1200
Code TypePowertrain
DIY RepairProfessional

⚡ Common Causes

⚠️ Symptoms

✅ How to Fix — Step by Step

  • Step 1:Clear codes and allow ECM to relearn
  • Step 2:Check battery and charging system voltage
  • Step 3:Replace ECM if error persists
💡 Pro Tip: A weak battery or recent battery disconnection is a common trigger - check charging system voltage before assuming ECM failure.

Repair Cost Estimate

Full Repair Estimate
$300-$1200
DIY Possible?
PRO
Severity
Critical

Frequently Asked Questions

What does OBD2 code P0603 mean?+
P0603 stands for Internal Control Module Keep Alive Memory Error. The ECM's keep-alive memory (KAM), which stores learned values like fuel trims, has failed.
What causes code P0603?+
Battery disconnection issues; Voltage drop/spike; Failed ECM memory chip
How do I fix code P0603?+
Clear codes and allow ECM to relearn; Check battery and charging system voltage; Replace ECM if error persists
How much does it cost to fix P0603?+
Estimated repair cost for P0603 is $300-$1200.
Is P0603 DIY-friendly?+
P0603 typically requires professional equipment and a qualified mechanic.

AI Diagnosis

Related Codes

P0606PCM Processor Fault
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P0601Internal Control Module Memory Check Sum Error
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P0602Control Module Programming Error
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P0604Internal Control Module Random Access Memory Error
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P0605Internal Control Module Read Only Memory Error
Critical
P0607Control Module Performance
Critical