Powertrain, generic · Hybrid propulsion

P0A40 Drive Motor A Position Sensor Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A40 means the resolver of motor A still delivers a signal, but its quality is poor or implausible. GM calls this a degraded signal: the sine or cosine value exceeds 4.0 V, judged within 0.2 to 0.4 s of a 2 s window (Type A, one trip in 2016; Type B, two trips on the 2013 mild hybrid). Mitsubishi (2023 Outlander PHEV front motor) sets it when sine or cosine leaves the 2.1 to 2.9 V band for 0.17 s. Audi lists P0A4000 with an implausible signal on the A7 and Q5 e quattro and replaces rotor position sensor G713 after checking gold-plated connector pins; Bentley pairs it with P0C5100/P0C5B00 and inspects connectors for pin drag. P0A3F is the hard signal loss. Expect a drive system warning or no start.

Likely causes

Rotor position sensor (resolver) delivering a degraded signal, e.g. Audi G713
Worn, loose or contaminated contacts in the resolver connectors (Audi, Bentley)
Sensor wires pinched or misrouted on the gearbox housing after a repair
Faulty resolver evaluation in the inverter/motor control module

Symptoms

  • Drive system fault message in the instrument cluster
  • Vehicle cannot be started or will not enter ready mode
  • Electric drive disabled or torque jerks while driving

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–5,000
Time2–10 h

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

Parts involved

drive motor arotor position sensorresolverwiring harness

Related codes

P0A3FP0A41P0A42P0A43P0A46P0C51P0A2E

References: gsi.ext.gm.com, gsi.ext.gm.com, mitsubishitechinfo.com, static.nhtsa.gov.