P0618: The alternative fuel control unit has a fault in the memory that retains
The alternative fuel control unit has a fault in the memory that retains settings when the car is off. It may clear after erasing the fault and disconnecting the battery briefly. If it returns, check the unit.
| Code | P0618 |
|---|---|
| System | Engine and transmission |
| Group | P06xx, Control unit and auxiliary outputs |
| Type | Generic: it means the same on every make |
How to read and clear P0618 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0618 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P0614 The engine control unit and the gearbox control unit are incompatible
- P0615 Starter relay: circuit fault
- P0616 Starter relay: circuit low
- P0617 Starter relay: circuit high
- P0619 The alternative fuel control unit has a RAM or ROM memory fault
- P061A The internal control unit torque gives readings outside the normal range
- P061B The engine control unit is calculating engine torque incorrectly
- P061C The internal control unit motor speed gives readings outside the normal range
- P0600 Serial communication link fault
- P0601 Internal control module memory checksum error
- P0602 Control module programming error
- P0603 Internal control module keep alive memory (KAM) error
What does code P0618 mean?
The alternative fuel control unit has a fault in the memory that retains settings when the car is off. It may clear after erasing the fault and disconnecting the battery briefly. If it returns, check the unit.
How do you clear P0618?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0618 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
