Faulty internal temperature sensor inside the PCM, ECM, or TCM; Corroded, loose, or damaged wiring or connectors at the module; Poor electrical ground connection to the module; Overheating of the module due to a blocked cooling path or engine bay heat; Internal circuit board fault or solder joint failure within the module; Software or calibration issue in the module requiring reflash; Voltage supply or reference signal instability affecting sensor readings

DTC codes / P06xx · Computer and output circuits / P0667

P0667PCM/ECM/TCM Internal Temperature Sensor Range/Performance

Q: What does code P0667 mean?

PCM/ECM/TCM Internal Temperature Sensor Range/Performance. P0667 indicates that the powertrain control module (PCM), engine control module (ECM), or transmission control module (TCM) has detected an out-of-range or erratic signal from its internal temperature sensor. The computer compares the sensor's output against expected values and sets this code when the reading falls outside the normal operating window or behaves unpredictably.

P0667 indicates that the powertrain control module (PCM), engine control module (ECM), or transmission control module (TCM) has detected an out-of-range or erratic signal from its internal temperature sensor. The computer compares the sensor's output against expected values and sets this code when the reading falls outside the normal operating window or behaves unpredictably.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Symptoms you may notice

Illumination of the check engine light or service engine soon light
Often no symptoms besides the warning light
Intermittent rough running or stalling when the module is hot
Transmission shifting irregularities if the TCM is affected
Reduced fuel economy or driveability due to incorrect temperature compensation
Hard starting or no-start condition in extreme cases

Common causes, most likely first

Faulty internal temperature sensor inside the PCM, ECM, or TCM
Corroded, loose, or damaged wiring or connectors at the module
Poor electrical ground connection to the module
Overheating of the module due to a blocked cooling path or engine bay heat
Internal circuit board fault or solder joint failure within the module
Software or calibration issue in the module requiring reflash
Voltage supply or reference signal instability affecting sensor readings

How to diagnose and fix it

Verify the code with a scan tool and check for any related codes in other modules
Inspect the module's electrical connectors and wiring for corrosion, looseness, or damage
Check and clean the module's ground connections to ensure a solid return path
Measure the sensor's signal circuit resistance and compare to manufacturer specifications
Monitor live data for the internal temperature sensor to see if the reading is erratic or stuck
If the sensor is internal and accessible, replace it; otherwise, the module may require replacement or repair
After repair, clear codes and perform a road test to confirm the fix and ensure the code does not return

When the module itself is the culprit

A common oversight is condemning the module immediately; always rule out wiring and ground issues first because they can mimic an internal sensor failure.
The internal temperature sensor is often not serviceable separately, meaning the entire module may need replacement, but some modules can be repaired by a specialist.
Heat soak after engine shutdown can cause intermittent failures that only appear when the module is hot, so testing when cold may miss the fault.
This code can be set by a low battery or charging system issue that causes voltage spikes, so check the battery and alternator before replacing the module.
On some vehicles, the internal temperature sensor is part of a circuit that also monitors other parameters, so a failure may also trigger related codes like P0666 or P0668.

Can I keep driving with P0667?

You can generally continue driving with this code, but avoid heavy loads or long trips until it is diagnosed, as the fault may cause driveability issues or leave you stranded if the module fails completely.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.