P2E21 code meaning
Drive Motor A Phase Y Current Sensor Circuit Low
Powertrain system Generic code P2Exx codes Check engine light
What P2E21 means
P2E21 records that the phase Y current sensor of drive motor A reports a value under the bottom of its scale. No manufacturer documents P2E21 publicly. GM's eAssist logic shows a clean way to test for this: the low and high checks of its U and W sensors run while PWM output is disabled, so the inverter is not switching and no phase current can flow. A reading below -440 A in 4 of 6 samples, one every 10.4 ms, then sets the U-phase code as two-trip Type B. Anything that far out at rest can only come from the measuring chain, for example a grounded signal line or a dead sensor supply. Too little real current in phase Y is a different fault, P2C6D. In a Mitsubishi Electric design, X, Y and Z form the second star-connected set. High side: P2E22; X and Z low: P2E1D, P2E25.
P2E21 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 P2E21
- Hybrid warning lamp and MIL
- Electric drive limited
- Engine runs more often than usual on hybrids
Common causes of P2E21
- Most likelyPhase Y sensor signal shorted to ground
- PossibleSensor supply voltage missing
- PossiblePhase Y current sensor failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor a phase y current sensorWiring harnessHybrid control module
What each part of P2E21 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 21 | The exact fault in that area. |
What to do next
- Note P2E21 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 P2E21
What does P2E21 mean?
P2E21 means "Drive Motor A Phase Y Current Sensor Circuit Low". P2E21 records that the phase Y current sensor of drive motor A reports a value under the bottom of its scale. It is a generic code, so it means the same on every make.
Is it safe to drive with P2E21?
Drive gently and only to a workshop. With P2E21 the car can go into limp mode (reduced power) to protect itself.
Will P2E21 fail an emissions test?
Yes, it can. P2E21 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 P2E21 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P2E21 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.