What it means
Same as P0666 with the signal in plausible range yet not matching the engine bay environment.
At a glance
- Usually lights the check-engine light
How it works
The PCM, ECM, or TCM monitors its internal temperature sensor to track heat inside the control module. P0667 sets when the sensor signal is present but its value or response does not meet the module's expected range or performance pattern.
Common causes
Most likely first.
- Internal temperature sensor drift or failure
- Module power or ground problem
- Damaged internal connection
- Control module fault
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
How to diagnose it
- Save freeze-frame data and scan all modules for related faults before clearing anything.
- After the vehicle has cooled and sat, compare the reported module temperature with ambient temperature, then observe whether the reading changes plausibly as the module warms.
- Inspect the control module's connectors and nearby wiring for moisture, corrosion, loose pins, or damage that could distort the signal.
- Check module power and ground under load against the manufacturer's specification, because unstable supply can affect the temperature reading.
- If the external connections and supply are sound, use vehicle-specific service information to assess the internal sensor response and determine whether the module is faulty.
Common fixes
- Clean and secure a contaminated or loose module connector.
- Repair a damaged connector or wiring and restore sound module power and ground.
- Replace or repair the control module if its internal temperature reading is confirmed to drift or respond incorrectly.
- Carry out any required module reset, programming, or relearn after repair.
Can I keep driving?
If it runs normally, drive only as needed and avoid heavy loads or long trips until the temperature-monitoring fault is resolved. Limp mode, stalling, or a no-start condition can develop if the module detects a problem or overheats.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.