P0A40: Drive Motor A Position Sensor Circuit Range/Performance
What to do
The same rule as the base code, stated harder: this variant is where healthy resolvers get condemned. The harness and its shielding are tested first.
What this code means
The rotor position signal is electrically alive but implausible — an angle that jumps, sticks or disagrees with the motor's actual behaviour.
A resolver reports angle as the relationship between induced voltages, so anything degrading one winding's signal — a chafed wire, a corroded pin, interference from a damaged shield — skews the computed angle while every individual wire still conducts. That is what makes this variant a wiring code wearing a sensor's name: the resolver is passive and rarely wrong, the path its signals travel is neither. See P0A3F for the family's economics.
Likely causes
Start here
- Chafed harness between transaxle and inverter · moderate
- Corroded or loose connector · easy
Less common
- Damaged sensor cable shielding · moderate
- Faulty motor position sensor · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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