P0A59 is the general circuit fault of the current sensor on the hybrid generator, the electric machine driven by the engine that charges the battery and often starts the engine. Its inverter uses the current reading to control generator torque. No manufacturer documents P0A59 publicly with criteria. Patents describe the same sensing on generators: Toyota for a motor that also works as an engine-driven generator, Hyundai for the hybrid starter-generator, where two phases are measured and the third is calculated, and Caterpillar for generator and traction motor sensors. CARB requires circuit checks of hybrid input components. P0A5A is plausibility, P0A5B/P0A5C low and high. Without a valid reading the generator is disabled, so charging and engine start can be affected.
Medium severity. Can I keep driving?If the battery warning light comes on, you could get stranded. Turn off electrical accessories and go straight to a repair shop.
Symptoms
- Hybrid warning and MIL
- Engine runs constantly or the high-voltage battery is no longer charged
- Vehicle may not enter ready mode
Most likely causes
- Generator current sensor failed (usually inside the inverter)
- Sensor supply or signal line interrupted or shorted
- Evaluation circuit on the generator control board faulty
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0A59 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- A: Hybrid or air and fuel
- 59: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0A59?
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 P0A59?
The most common causes are: generator current sensor failed (usually inside the inverter); sensor supply or signal line interrupted or shorted; evaluation circuit on the generator control board faulty.
Related codes
- P0A5AGenerator Current Sensor Circuit Range/Performance
- P0A5BGenerator Current Sensor Circuit Low
- P0A5CGenerator Current Sensor Circuit High
- P0A51Drive Motor A Current Sensor Circuit
- P0A7AGenerator Inverter Performance
Sources
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.