Check Engine Code
P0603
Internal Control Module KAM Error
Severity: high
DIY difficulty: 5/5
Typical cost: $150–$1500
What P0603 means
Keep-Alive Memory (KAM) holds learned values like fuel trims and throttle adaptation. P0603 means the ECM can't store/retrieve from KAM correctly.
Symptoms
- CEL
- Fuel trims reset every drive
- Slight drivability issues
Likely causes (most common first)
- ECM internal fault
- Battery voltage issues
- Recent battery disconnection
Can I keep driving?
High — risk of damage if ignored
Typical repair cost
DIY fixes can start near $150 (parts only). Shop repairs for P0603 typically run up to $1500 depending on the underlying cause and vehicle. Start with the most common cause — ECM internal fault — before throwing parts at it.
Recommended parts & tools for P0603
Our buyer’s guides cover the tools and parts that pair with AXLY:
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