P0A02Motor Electronics Coolant Temperature Sensor A Circuit Low
- 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
- The signal voltage of the coolant temperature sensor in the electronics loop sits below its valid window. Because the sensor is an NTC thermistor, a low voltage means an implausibly hot reading, typically a short to ground. GM uses P0A02 on the 2013 Two-Mode hybrid Tahoe, Yukon, Escalade, Silverado and Sierra: the converted temperature reaches the 162.1 °C limit in 30 of 50 samples taken every 100 ms, after more than 10 s of propulsion active and with no intake air sensor fault (P0112, P0113) present. It is a Type B code with MIL after two trips. The opposite fault is P0A03. Expect a warning light and possibly reduced electric power.
- What you may notice
- Check engine or hybrid warning light
- Displayed electronics temperature extremely high although the system is cool
- Cooling fans and pump running at full output, drive power limited
- Likely causes
- LikelySignal wire chafed through and shorted to ground
- PossibleInternal short in the thermistor
- PossibleMoisture or coolant in the connector bridging signal to ground
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.