P0A01: Motor Electronics Coolant Temperature Sensor A Circuit Range/Performance

The sensor delivers a value inside its electrical range, but it does not fit the other temperatures in the vehicle. GM uses this code on the 2013 Two-Mode hybrid Tahoe, Yukon, Escalade, Silverado and Sierra as a cold-start test: after the vehicle has stood for more than 28,800 s (8 h), the power electronics coolant temperature at power-up may differ from engine coolant temperature by no more than 30 °C, provided engine coolant and intake air agree within 15.75 °C. A failure is a Type B code with MIL after two trips. Nissan describes a similar comparison between inverter coolant and power element temperatures. Hard electrical faults are P0A02 and P0A03.

Medium severity. Can I keep driving?Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

Symptoms

Check engine light after two trips
Often no noticeable change in driving behaviour
Electric drive power limited when the electronics are hot

Most likely causes

Sensor characteristic drifted, reading offset against the other temperature sensors
Added resistance at a corroded connector shifting the reading
Low coolant or air pocket at the sensor in the electronics loop
Fault actually in the engine coolant or intake air sensor used for comparison

What to check, in order

Start with the simplest. You can tick off each step.

With the engine cold, check the coolant level; never do this when the system is hot
Compare the reading with other engine data while varying the engine speed.
Check the actual temperature in live data
Make sure the fan comes on when it should
Check the thermostat and connector
Measure the sensor and replace it if its readings do not make sense

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P0A01 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
A: Hybrid or air and fuel
01: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0A01?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P0A01?

The most common causes are: sensor characteristic drifted, reading offset against the other temperature sensors; added resistance at a corroded connector shifting the reading; low coolant or air pocket at the sensor in the electronics loop.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.