P0E91 code meaning
Drive Motor B Inverter Voltage Sensor B Circuit
Powertrain system Generic code P0Exx codes Check engine light
What P0E91 means
P0E91 is the circuit code for the second DC voltage channel, sensor B, in the inverter of drive motor B, usually the second electric machine or the rear axle motor. It applies when this signal is absent or electrically unusable without a more precise verdict; its partner channel A is coded P0DA3, and the matching code for drive motor A is P0E8C. No manufacturer documents P0E91 or its B-sensor siblings for motor B publicly. Mitsubishi illustrates the frame with sensor A of the rear motor on the 2023 Outlander PHEV: the rear motor unit reports its inverter voltage, which the front power electronics compare with their own capacitor values. CARB requires inputs of hybrid drive components to be monitored for circuit faults. Motor B is then usually switched off, and the car may drive with reduced power.
P0E91 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0E91
- Hybrid or EV warning with MIL
- Loss of the second drive motor (for example no all-wheel drive), reduced power
Common causes of P0E91
- Most likelyVoltage channel B measuring circuit in the motor B inverter defective
- PossibleConnector or harness of the motor B inverter loose or damaged
- Less likelySoftware fault in the motor B control unit
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor b inverter voltage sensor bWiring harnessHybrid control module
What each part of P0E91 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 91 | The exact fault in that area. |
What to do next
- Note P0E91 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 P0E91
What does P0E91 mean?
P0E91 means "Drive Motor B Inverter Voltage Sensor B Circuit". P0E91 is the circuit code for the second DC voltage channel, sensor B, in the inverter of drive motor B, usually the second electric machine or the rear axle motor. It is a generic code, so it means the same on every make.
Is it safe to drive with P0E91?
Drive gently and only to a workshop. With P0E91 the car can go into limp mode (reduced power) to protect itself.
Will P0E91 fail an emissions test?
Yes, it can. P0E91 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 P0E91 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P0E91 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.