P0605 Internal control module read only memory (ROM) error
What P0605 means
The engine control unit checks its permanent program memory and has found it corrupt. Sometimes a reflash with the correct software fixes it; otherwise the unit needs repair or replacement.
P0605 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Typical repair cost
- 150–1200 €
- Workshop time
- 1–4 h
- Repair difficulty
- Hard
- DIY possible
- No
- Check engine light
- Yes
- Affects emissions test
- No
- Limp mode possible
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Engine may not start
- Stalling or poor running
- Limp mode
Common causes
- Failed or interrupted software update
- Internal memory chip failure
- Voltage spike from jump-starting or welding
- Water ingress into the control unit
Can I keep driving with P0605?
Have it checked immediately. The car may stop running or fail to restart.
What to check first
- Check battery voltage and ECU grounds
- Find out whether a software update was recently done
- Have the control unit reprogrammed with the correct software
- Replace and code the control unit if the error remains
Related codes
- P0604 Internal control module random access memory (RAM) error
- P0606 Control module processor fault
- P0603 Internal control module keep alive memory (KAM) error
- P0607 Control module performance
- P0602 Control module programming error
- P0601 Internal control module memory checksum error
- P0600 Serial communication link
- P0610 Control module vehicle options error
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
Updated: