Powertrain, generic · Hybrid propulsion

P0A01 Motor Electronics Coolant Temperature Sensor A Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

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

Symptoms

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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

motor electronics coolant temperature sensorhybrid inverterwiring harness

Related codes

P0A00P0A02P0A03P0A04P2BD8P0A93

References: gsi.ext.gm.com, patents.google.com, law.cornell.edu.