P0606
Control Module Processor
Powertrain control module (PCM/ECM)
Generic OBD-II
High
What it means
P0606 indicates an internal processor fault inside the engine/powertrain control module (ECM/PCM) — the computer that runs the engine. Because everything depends on it, the engine may run erratically, stall, or fail to start, and unrelated codes can appear. Check the module's power, grounds, and connectors before assuming the ECM itself has failed.
High
Can I keep driving? No — an internal processor fault in the ECM/PCM can make the engine run erratically, stall, or not start; treat it as a stop-and-diagnose condition and avoid driving until it's resolved.
Common symptoms
What you'll notice
- Check-engine light on (may stay on constantly)
- Engine runs poorly, stalls, or won't start
- Reduced power or erratic behavior
- Other seemingly unrelated codes set at the same time
Common causes
Most likely first
- Poor ECM power or ground (corroded/loose connectors, bad grounds)Likely
- Damaged or corroded ECM wiringCommon
- Water or physical damage to the moduleCommon
- Internal ECM/PCM failureLess often
How to diagnose & fix
Work through it in order
- Check battery voltage and the ECM's power and ground circuits first.
- Inspect ECM connectors and wiring for corrosion, damage, or moisture.
- Clear the code and see if it returns immediately (hard fault) or was a glitch.
- Reflash/reprogram the ECM if the manufacturer has an update.
- Replace and program the ECM if it's confirmed failed.
FAQ
Quick answers
Is it safe to drive with P0606?+
No. An internal control-module fault can cause stalling or a no-start without warning. Have it diagnosed before relying on the vehicle.
Can I just clear P0606?+
You can try — sometimes it's a one-time glitch from a low battery or bad connection. If it comes straight back, the module or its wiring needs repair.
Related codes
Often seen with P0606
Read & clear P0606 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX