P2E7B

Code

Generic P — Powertrain

Drive Motor A Excitation Current Sensor Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 41 RU: 26

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Page language: EN

Causes

Open, short or high resistance in the excitation current sensor wiring or connector
Corroded, bent, or loose pin at the sensor or control module connector
Faulty excitation/current sensor (Hall or shunt type) on Drive Motor A
Faulty inverter/inverter control module or internal sensor electronics
Poor ground or missing sensor reference supply
Intermittent connection due to vibration or damaged harness

Symptoms

MIL / electric powertrain warning lamp illuminated
Reduced or limited drive (limp) mode or reduced motor torque
Loss or reduction of regenerative braking
Drive motor disabled or degraded performance
Possible stored additional hybrid/electric system codes
Intermittent fault or faults that occur under vibration or load

What to check

Read freeze frame and live data with a capable scan tool; note conditions when code set (speed, torque, SOC)
Visual inspection of Drive Motor A harness, connectors, and sensor for damage, corrosion, or loose pins
Check for supplemental hybrid/electric system warnings and related codes
Inspect fuses, contactors, and HV interlock related to inverter power and sensor supplies
Backprobe sensor connector to observe live signal while operating (use appropriate HV/ISOLATED tools)
Compare sensor signal to known-good reference or the same sensor on Drive Motor B (if present)

Signal parameters

Typical sensor type: Hall-effect or shunt-based current sensor producing analog voltage proportional to excitation current
Expected signal range (typical): ~0.1–4.9 V (sensor-dependent) or 0–5 V scale — consult vehicle-specific data
Reference supply: stable sensor supply/reference and ground must be present (often 5 V or vehicle ground reference)
Signal should be smooth and proportional to commanded excitation — not open (near 0 V) or shorted (stuck near supply)
If sensor is shunt-based, expect low resistance across shunt (milliohms) measured at manufacturer spec

Diagnostic algorithm

Safety first: follow high-voltage system lockout and isolation procedures before any contact with HV components
Connect a diagnostic scan tool that supports HV drive/inverter data and confirm P2E7B is current or stored
Record freeze-frame and live data for excitation current sensor, motor torque command, inverter status, and battery voltage
Perform visual inspection of wiring and connectors between Drive Motor A sensor and inverter/control module; repair any damage
With vehicle safe and low-voltage circuits accessible, backprobe the sensor connector and verify sensor supply/reference and ground voltages per manufacturer spec
Measure sensor output voltage while commanding motor excitation (use scan tool or controlled test) and verify it changes proportionally to current demand
Check continuity and resistance of sensor wiring harness between sensor and inverter; look for opens, shorts to ground, or shorts to battery supply
If available and safe, compare the behavior to Drive Motor B or a known-good sensor
If wiring and supply are good, replace the excitation current sensor and retest
If fault persists after sensor replacement, suspect inverter/internal control module failure — consult manufacturer repair procedures for module testing or replacement
Clear codes and perform road/drive cycle to confirm repair

Likely causes

Damaged or corroded sensor connector or pin
Open or short in the sensor signal, power, or ground circuit
Failed excitation/current sensor hardware
Fault inside the inverter/control module causing incorrect sensor reference or processing

Fault status

⚠️ Status

Drive Motor A excitation current sensor circuit malfunction detected. Sensor signal out of expected range or circuit fault. Inverter/control module may limit or disable motor operation and store this DTC.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1.5 - 4.0 hours