P0618
Alternative Fuel Control Module KAM Error
The control module for alternative fuel (CNG, LPG, hydrogen) reports a Keep-Alive-Memory error - persistent calibration values are corrupt or unreadable. Adaptive learning is reset.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Common causes
Ordered by how often each turns out to be the cause.
- KAM contents corruptedCommon
- Module software outdated, reflash may resolveLess likely
- Supply voltage outside specificationLess likely
Parts involved
- Alternative Fuel Control Module
P0618 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.