P0606 Code: ECM/PCM Processor Fault
🟠 Moderate severity · drivable
Drivable if the engine runs, but the PCM itself is failing, so expect problems until it's replaced.
What P0606 means
The engine control module (PCM) has detected a fault in its own processor — the main chip that runs the whole show. This is usually a sign the PCM is failing.
Symptoms
- Check engine light is on
- Erratic or intermittent running
- Multiple unrelated codes
- Possible stalling or no-start
Common causes
- most common: Faulty engine control module (PCM)
- common: Poor PCM grounds or low voltage
- less common: Failed software update
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check PCM grounds and battery voltage | Yes | $0–50 |
| Replace the engine control module | Mechanic | $500–1500 |
Frequently asked questions
Can I drive with a P0606 code?
Sometimes, but the PCM is failing and the vehicle may strand you. Replace it soon.
What is the most common cause of P0606?
A faulty engine control module.
How much does it cost to fix a P0606?
Typically $500–$1,500 for a replacement PCM, plus programming.
Related codes
P0600
P0600 Code: Serial Communication Link Malfunction
P0601P0601 Code: Internal Control Module Memory Check Sum Error
P0605P0605 Code: Internal Control Module Read Only Memory (ROM) Error
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.