P0A55 code meaning
Drive Motor B Current Sensor Circuit
Powertrain system Generic code P0Axx codes Check engine light
What P0A55 means
P0A55 is the general circuit fault of the current sensor that measures the current of drive motor B, typically the second traction motor, for example on a rear axle. The inverter needs this signal for torque control and to protect its power switches. No manufacturer documents P0A55 publicly. A Toyota patent shows the principle behind such checks: a control sensor and a monitoring sensor watch the same motor current, and a sensor stuck in its ground-short range or a lasting gap between the two leads to the relays opening. CARB requires circuit checks of hybrid input components. P0A56 is plausibility, P0A57/P0A58 low and high; P0A51 is the same fault on motor A. Usually drive motor B is switched off and the car drives on reduced power.
P0A55 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0A55
- Hybrid or electric drive warning with MIL
- Drive motor B disabled, loss of electric all-wheel drive or reduced power
Common causes of P0A55
- Most likelyCurrent sensor of drive motor B failed (usually inside the inverter)
- PossibleSensor supply or signal line interrupted or shorted
- Less likelyEvaluation circuit on the motor B control board faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor b current sensorWiring harnessHybrid control module
What each part of P0A55 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 55 | The exact fault in that area. |
What to do next
- Note P0A55 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0A55
What does P0A55 mean?
P0A55 means "Drive Motor B Current Sensor Circuit". P0A55 is the general circuit fault of the current sensor that measures the current of drive motor B, typically the second traction motor, for example on a rear axle. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A55?
Drive gently and only to a workshop. With P0A55 the car can go into limp mode (reduced power) to protect itself.
Will P0A55 fail an emissions test?
Yes, it can. P0A55 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0A55 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P0A55 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.