Error code

OBD2 P0603

OBD2P0603
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Internal Control Module Keep Alive Memory (KAM) Error.

Severity

moderateCan drive, but may experience performance issues and increased fuel consumption.

Summary

P0603 indicates an Internal Control Module Keep Alive Memory (KAM) Error in the Engine Control Module (ECM). This means the ECM is operating on default parameters instead of learned data from driving conditions.

Symptoms

  • Check engine light
  • Other warning lights may illuminate
  • Engine stalling
  • Intermittent engine stumble
  • Rough idle
  • Increased fuel consumption

Common Causes

  • Aftermarket tuning products
  • Faulty wiring related to the ECM
  • Water intrusion of the ECM
  • Faulty wiring of the ignition system allowing interference
  • Faulty ECM

Diagnosis

  1. Inspect battery cables for corrosion or looseness.
  2. Check wiring harness going into the fuse box for damage.
  3. Carefully inspect ECM and surrounding wiring for water intrusion or defects.
  4. Examine spark plug wires and caps for cracks or insulation issues.
  5. If no other symptoms, suspect faulty ECM.

Fixes

  • Remove aftermarket tuning products if present.
  • Replace faulty wiring or components as needed.
  • Reflash the ECM software at a dealership (if applicable).

FAQ

What is Keep Alive Memory (KAM)?

KAM stores learned data from driving conditions to optimize vehicle performance.

Can P0603 be caused by water damage?

Yes, water intrusion into the ECM can cause this code.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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