P2E28 code meaning
Drive Motor A Excitation Current Sensor Performance
Powertrain system Generic code P2Exx codes Check engine light
What P2E28 means
P2E28 concerns a drive motor with an electrically excited rotor, the type Nissan uses in the Ariya and BMW in its fifth-generation eDrive. Such a rotor carries a field coil that receives direct current through brushes and slip rings; a sensor measures that current for the closed field-control loop. P2E28 means the sensor signal is electrically valid but does not make sense, for instance it disagrees with a second sensor or with what the commanded duty cycle should produce. CARB wants rationality faults stored apart from circuit faults. No manufacturer documents P2E28 publicly, nor its thresholds. Wiring faults are P2E7B, P2E29 and P2E2A; a real overcurrent is P2E2B. Without a trusted reading the field cannot be regulated, so expect reduced or no drive power.
P2E28 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 P2E28
- Electric drive warning or service message
- Noticeably reduced drive power
- Vehicle may refuse to drive or stop driving
Common causes of P2E28
- Most likelyExcitation current sensor drifted (offset or gain no longer correct)
- PossibleFaulty excitation power stage, so actual and expected current differ
- PossibleWorn brushes or dirty slip rings changing the field circuit resistance
- Less likelyInverter or motor control software fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor a excitation current sensorDrive motor a excitation circuitHybrid control module
What each part of P2E28 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 28 | The exact fault in that area. |
What to do next
- Note P2E28 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 P2E28
What does P2E28 mean?
P2E28 means "Drive Motor A Excitation Current Sensor Performance". P2E28 concerns a drive motor with an electrically excited rotor, the type Nissan uses in the Ariya and BMW in its fifth-generation eDrive. It is a generic code, so it means the same on every make.
Is it safe to drive with P2E28?
Drive gently and only to a workshop. With P2E28 the car can go into limp mode (reduced power) to protect itself.
Will P2E28 fail an emissions test?
Yes, it can. P2E28 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 P2E28 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P2E28 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.