P0605 — Internal Control Module Read Only Memory (ROM) Error
Category: Powertrain Severity: High
Updated:
DTC code P0605 means: Internal Control Module Read Only Memory (ROM) Error. It falls under the "Powertrain" category, with an estimated severity of High. Common causes include eCM/PCM software not programmed correctly or corrupted, low or unstable battery voltage during a previous update and internal ECM/PCM hardware fault; it's worth confirming the diagnosis before replacing parts.
Possible causes
- ECM/PCM software not programmed correctly or corrupted
- Low or unstable battery voltage during a previous update
- Internal ECM/PCM hardware fault
Symptoms
- Check engine light on
- Erratic engine behavior or stalling
- Other modules may also show faults
- Vehicle may fail to start in severe cases
How to diagnose it step by step
- Check battery and grounds.
- Reflash the ECU.
- Replace the ECU if the error persists.
How to fix it
This code points to the engine computer itself. Check battery voltage and connections first (a weak battery during a software update is a common cause). If the fault persists, the ECM/PCM usually needs reprogramming or replacement at a specialized workshop or dealer.
Estimated repair cost
$100–1,500.
Frequently asked questions
What does DTC code P0605 mean?
Internal Control Module Read Only Memory (ROM) Error.
Is code P0605 serious?
Severity High. Have it checked as soon as possible, especially if it affects safety or the catalytic converter.
Can I keep driving with code P0605?
Not recommended.
Related codes
P0604 P0606 P0603 P0602 P0601 P0600 P0615 P0620 P0627 P0641
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