Powertrain, generic · Hybrid propulsion

P0AF1 Drive Motor Inverter Temperature Sensor A Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0AF1 is meant for an inverter temperature sensor A signal that jumps or drops out briefly instead of failing permanently. Inverter heat sinks are liquid-cooled and change temperature smoothly, so sudden steps point to a contact problem or an internal fault in the sensing circuit. No manufacturer documents this exact code publicly; GM's hybrid tables cover sensor A only with the plausibility, low and high codes P0AEE, P0AEF and P0AF0. GM's method for erratic battery sensors, such as P0AEC, sums signal changes over 10-sample windows and fails after 4 of 5 bad windows, which shows how such a check usually works. CARB requires hybrid sensor inputs to be monitored for this kind of fault. Freeze-frame data help, since the fault often comes and goes.

Likely causes

Loose or corroded connector at the inverter module
Intermittent fault inside the power inverter module
Electrical interference on the sensor signal

Symptoms

  • Warning lamp that comes and goes
  • Brief power reductions while driving
  • Jumping inverter temperature in live data

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–4,000
Time1–6 h

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

Parts involved

drive motor inverter temp sensor ahybrid control modulewiring harness

Related codes

P0AEDP0AEEP0AEFP0AF0P0AF6

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