P0A4D: Generator Position Sensor Circuit Low

P0A4D reports a generator resolver signal stuck below its permitted range, as caused by a sine, cosine or excitation line shorted to ground or a winding short. No manufacturer documents this code publicly. Mitsubishi shows how the fault is judged but files it under its own codes: on the 2023 Outlander PHEV a sine or cosine voltage at or below 2.0 V for 0.21 s sets P0C66 or P0C6B instead of P0A4D. A Bosch patent describes distinguishing a short to ground from a short to supply by the offset of the receiver coil lines, which is the basis for low/high splitting. CARB requires such circuit checks for hybrid input components. P0A4E is the high side, P0A4B the general circuit fault, P0A4C plausibility. The hybrid system typically shuts the generator down and warns the driver.

Symptoms

• Hybrid system warning and MIL
• Generator disabled, engine-only or no-start condition

Most likely causes

• Sine, cosine or excitation line shorted to ground
• Moisture or corrosion in the resolver connector
• Shorted resolver winding inside the generator

What to check, in order

Start with the simplest. You can tick off each step.

1. Measure the voltage with the engine off and running
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Clean and tighten the terminals
4. Check the accessory belt
5. Run a battery load test
6. Check the alternator wiring

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0A4D means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• A: Hybrid or air and fuel
• 4D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0A4D?

If the battery warning light comes on, you could get stranded. Turn off electrical accessories and go straight to a repair shop.

What causes code P0A4D?

The most common causes are: sine, cosine or excitation line shorted to ground; moisture or corrosion in the resolver connector; shorted resolver winding inside the generator.

Related codes

• P0A4EGenerator Position Sensor Circuit High
• P0A4BGenerator Position Sensor Circuit
• P0A4CGenerator Position Sensor Circuit Range/Performance
• P0A4FGenerator Position Sensor Circuit Intermittent
• P0C66Generator Position Sensor Circuit A Low
• P0C6BGenerator Position Sensor Circuit B Low

Sources

• mitsubishitechinfo.com: N503240240000800USA
• patents.google.com: en
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.