P0618 code meaning
Alternative Fuel Control Module KAM Error
Powertrain system Generic code P06xx codes Check engine light
What P0618 means
CARB treats gas-fuelled vehicles (CNG, LPG, also the gas mode of bi-fuel cars) like gasoline cars up to model year 2018 and under an approved manufacturer plan afterwards. P0618 is meant for vehicles with a separate control module for the alternative fuel: it reports an error in that module's keep alive memory, which holds learned values while the ignition is off and loses them when power is cut – the gas counterpart of P0603. No manufacturer was found that uses P0618 this way; Roush's Ford propane conversions, for example, report a failed gas module as U0108. One Chrysler bulletin lists 'P0618' with the title of P061B – apparently a typo, not a second meaning. Expect lost adaptations; bi-fuel cars may switch to gasoline. Check supply, fuse and ground of the gas module first.
P0618 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0618
- Check engine or gas system warning light
- Switch to gasoline, gas mode blocked (bi-fuel)
- Rough idle until values are relearned
- Often no symptoms
Common causes of P0618
- Most likelyPower interruption at the gas module (battery disconnected, fuse, loose contact)
- PossiblePoor supply, ground or corrosion at the module (underbody mounting)
- PossibleSoftware or programming fault of the gas module
- Less likelyInternal memory defect
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alternative fuel control moduleModule power supply
What each part of P0618 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| 18 | The exact fault in that area. |
What to do next
- Note P0618 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0618
What does P0618 mean?
P0618 means "Alternative Fuel Control Module KAM Error". CARB treats gas-fuelled vehicles (CNG, LPG, also the gas mode of bi-fuel cars) like gasoline cars up to model year 2018 and under an approved manufacturer plan afterwards. It is a generic code, so it means the same on every make.
Is it safe to drive with P0618?
Drive gently and only to a workshop. With P0618 the car can go into limp mode (reduced power) to protect itself.
Will P0618 fail an emissions test?
Yes, it can. P0618 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0618 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P0618 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.