P0603

Lack of proper voltage to the Keep Alive Memory connection on the PCM, Defective PCM Keep Alive Memory Module (KAM), Defective PCM ground circuit(s), Defective PCM controlled output devices

OBD-II diagnostic trouble code P0603indicates a fault detected by the vehicle's onboard computer. This code applies to all OBD-II compliant vehicles and should be addressed promptly to avoid potential engine or emissions system damage.

Severity Level 5 — Critical

This code indicates a critical issue that may cause severe engine damage or complete engine failure. Stop driving immediately and have the vehicle towed to a repair shop. Continuing to drive could result in catastrophic engine damage and costly repairs.

Common Symptoms

• Check engine light on
• Reduced fuel economy
• Possible rough idle or hesitation

Possible Causes

• Lack of proper voltage to the Keep Alive Memory connection on the PCM, Defective PCM Keep Alive Memory Module (KAM), Defective PCM ground circuit(s), Defective PCM controlled output devices
• Manufacturer-specific condition
• Fault in related component or circuit

Common Fixes

• Diagnose with professional OBD2 scan tool
• Check manufacturer TSBs
• Inspect related components per service manual

Estimated Repair Cost

These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.

Explore Repair Costs

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