P2E7B code meaning
Drive Motor A Excitation Current Sensor Circuit
Powertrain system Generic code P2Exx codes Check engine light
What P2E7B means
P2E7B is the general circuit fault of the measuring element for the DC field current in the rotor of drive motor A. It exists only in electrically excited synchronous motors, whose rotor field comes from a winding, as in Renault's Megane E-Tech, Nissan's Ariya and BMW's fifth-generation eDrive. The controller stores P2E7B when the signal is missing or unusable without a clear low or high reading, e.g. after a lost supply, a broken connection or a dead sensor. In TI's excitation stage a single or a pair of sensors, shunt amplifiers or isolated Hall parts, closes the field loop. No manufacturer documents P2E7B publicly. Low and high signal are P2E29 and P2E2A, implausible values P2E28. Without a trusted value the field is cut, as Audi describes for fault signals, and the motor stops pulling.
P2E7B 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 P2E7B
- Electric drive warning lamp and MIL
- Noticeably reduced power or no drive from motor A
- Vehicle may refuse to enter ready mode
Common causes of P2E7B
- PossibleSupply or reference of the excitation current sensor lost
- PossibleOpen or corroded connection between sensor and motor controller
- PossibleExcitation current sensor or its isolated amplifier failed
- Less likelyMeasuring input inside the inverter or motor controller defective
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 sensorWiring harnessHybrid control module
What each part of P2E7B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7B | The exact fault in that area. |
What to do next
- Note P2E7B 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 P2E7B
What does P2E7B mean?
P2E7B means "Drive Motor A Excitation Current Sensor Circuit". P2E7B is the general circuit fault of the measuring element for the DC field current in the rotor of drive motor A. It is a generic code, so it means the same on every make.
Is it safe to drive with P2E7B?
Drive gently and only to a workshop. With P2E7B the car can go into limp mode (reduced power) to protect itself.
Will P2E7B fail an emissions test?
Yes, it can. P2E7B 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 P2E7B to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P2E7B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.