P0667Control Module Internal Temperature Sensor A Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Control modules measure their own circuit board temperature with an internal sensor to protect output stages (overtemperature is P0634) and, in GM transmission modules, as a substitute for fluid temperature. In GM's 6T70/6T75 and related automatics the sensor sits in the transmission module inside the valve body, with no external wiring – so the repair is practically always the module or valve body assembly. P0667 is the plausibility check: GM compares the module (substrate) temperature with the transmission fluid temperature and the temperature measured at power-up. The Saab 9-4X sets it when, within 5 of 6 minutes, fluid and substrate differ by more than 20–50 °C and power-up and substrate by more than 8–10 °C (two trips); GM's 2019 table uses 3000 of 3750 samples. The module then uses the power-up temperature instead. Check the fluid temperature sensor (P0711) first – it is the comparison partner.
- What you may notice
- Engine or transmission warning lamp
- Harsher or delayed shifts (substitute temperature)
- Possibly P0711 as well
- Likely causes
- LikelyTransmission module or valve body (internal sensor) faulty
- PossibleTransmission fluid temperature sensor reads wrong (comparison partner)
- RareUnusual conditions (long standing in extreme cold or heat, fluid level or condition)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €400 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.