P2E7BDrive Motor A Excitation Current Sensor Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Electric drive warning lamp and MIL
- Noticeably reduced power or no drive from motor A
- Vehicle may refuse to enter ready mode
- Likely causes
- 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
- RareMeasuring input inside the inverter or motor controller defective
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.