P0A02 code meaning
Motor Electronics Coolant Temperature Sensor A Circuit Low
Powertrain system Generic code P0Axx codes Check engine light
What P0A02 means
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.
P0A02 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P0A02
- 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
Common causes of P0A02
- Most likelySignal wire chafed through and shorted to ground
- PossibleInternal short in the thermistor
- PossibleMoisture or coolant in the connector bridging signal to ground
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Motor electronics coolant temperature sensorHybrid inverterWiring harness
What each part of P0A02 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 02 | The exact fault in that area. |
What to do next
- Note P0A02 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0A02
What does P0A02 mean?
P0A02 means "Motor Electronics Coolant Temperature Sensor A Circuit Low". The signal voltage of the coolant temperature sensor in the electronics loop sits below its valid window. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A02?
Drive gently and only to a workshop. With P0A02 the car can go into limp mode (reduced power) to protect itself.
Will P0A02 fail an emissions test?
Yes, it can. P0A02 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0A02 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0A02 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.