P0605: Internal control module read only memory (ROM) error
The engine ECU has found an error in the memory holding its program. It may be fixed by reprogramming or may need the unit replaced.
| Code | P0605 |
|---|---|
| System | Engine and transmission |
| Group | P06xx, Control unit and auxiliary outputs |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0605 means
ROM is the memory where the ECU’s program is stored. This code means the ECU has checked it and found something wrong. Sometimes reloading the software is enough; if the memory itself is damaged, the ECU has to be replaced.
Most common causes
- Low battery or power loss during programming
- Corrupted software or a badly done software modification
- Moisture or corrosion in the ECU or its plug
- Unstable ECU supply or earth
- Internal ECU memory fault
Symptoms
- Engine warning light on
- Engine may not start or may stall
- Limp mode, lack of power or running faults
Can you drive with P0605?
With care The car could leave you stranded without warning. Drive carefully and only when essential until it is checked.
Open the bonnetthe in-depth explanation
How to check it
Check the battery and terminals first, clear the code and see if it returns. If it does, tell the garage whether the ECU has been reprogrammed or remapped, as that changes the diagnosis a lot.
How to read and clear P0605 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 P0605 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
- P0601 Internal control module memory checksum error
- P0602 Control module programming error
- P0603 Internal control module keep alive memory (KAM) error
- P0604 Internal control module random access memory (RAM) error
- P0606 ECM/PCM processor fault
- P0607 Control module performance
- P0608 The control unit vehicle speed output A has a fault
- P0609 There is a fault in control unit output B for the vehicle speed signal
- P0600 Serial communication link fault
- P0615 Starter relay: circuit fault
- P0616 Starter relay: circuit low
- P0617 Starter relay: circuit high
What does code P0605 mean?
ROM is the memory where the ECU’s program is stored. This code means the ECU has checked it and found something wrong. Sometimes reloading the software is enough; if the memory itself is damaged, the ECU has to be replaced.
Can you drive with P0605?
The car could leave you stranded without warning. Drive carefully and only when essential until it is checked.
How do you clear P0605?
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, P0605 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.
