P0607: Control Module Performance
Severity: medium
What it means: The engine computer (or another control module) failed one of its own internal self-checks. It sometimes means the computer is bad, but wiring, grounds, moisture and low voltage can set it too.
Safe to drive? Often yes if it drives normally, but get it checked soon. If the car loses power, stalls or goes into limp mode, stop driving it.
Common symptoms
- Check-engine light
- Sometimes no other symptoms
- Reduced power or limp mode on some cars
- Other warnings, such as rev match or emissions messages, turned off as a precaution
Likely causes, ranked
- Moisture or corrosion at the engine computer connector or fuse boxShop
- Wiring harness or ground problemShop
- Low or unstable 12V battery voltageDIY
- Faulty engine computer or softwareShop
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Vehicle-specific notes
- 2017–2025 Honda Civic Type R: An FK8 owner got P0607 after driving in rain, and the dealer suggested a new engine computer. Owners pointed first to a wiring harness bulletin for some 2017-2018 cars and to checking connectors for moisture. Read the full answer · Source
DIY or shop?
Testing the 12V battery and checking connectors for moisture is DIY. Harness repairs and engine computer replacement or programming are shop jobs.
Before you replace parts
- Read all stored codes and freeze-frame data. Fix misfire, fuel or sensor codes before chasing emissions codes.
- Check the simple things first: connectors, vacuum hoses, fluid levels and the gas cap.
- Ask about software updates and service bulletins before agreeing to a new engine computer.
- Clear the code only after a repair, then confirm it stays off after a few drives.
- Check your VIN for recalls and service bulletins.
Safety / mechanic note
Verify with a mechanic if you notice drivability changes, warning lights or overheating. A code points to a circuit or system, not always a specific part.
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