P0A4F: Generator Position Sensor Circuit Intermittent
What to do
Keep note of when starts fail — weather, temperature, what the car had just been doing. An intermittent resolver connection produces exactly the maddening sometimes-fault pattern that pattern-notes solve.
What this code means
The generator's rotor angle is dropping out and returning.
Intermittency convicts the harness, and this machine's version of the symptom is distinctive: engine starts that succeed sometimes and fail sometimes, tracking bumps, damp or temperature rather than anything about the engine. An inconsistent no-start is one of diagnosis's great time-sinks — this circuit deserves a place on its suspect list on any full hybrid.
Likely causes
Start here
- Intermittent wiring fault · moderate
- Corroded or loose connector · easy
Less common
- Water ingress into connector · easy
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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