Damaged or shorted phase Z cable between the inverter and the drive motor; Internal short or insulation breakdown in the drive motor A phase Z winding; Failed current sensor or signal circuit inside the inverter controller; Faulty inverter power module causing uncontrolled current flow in phase Z; Corroded or loose high-voltage connector pins at the motor or inverter; Coolant contamination or overheating of the inverter leading to component failure; Software calibration error in the inverter control module (rare but possible)

DTC codes / P2Cxx · Hybrid propulsion / P2C71

P2C71Drive Motor "A" Phase Z Current High

Q: What does code P2C71 mean?

Drive Motor "A" Phase Z Current High. P2C71 indicates that the inverter controller for drive motor A has detected an excessively high current in phase Z, which is one of the three motor windings. The computer compares commanded current against measured phase current and flags this code when the Z-phase current exceeds the calibrated threshold, pointing to a short, a failing inverter, or a wiring fault.

P2C71 indicates that the inverter controller for drive motor A has detected an excessively high current in phase Z, which is one of the three motor windings. The computer compares commanded current against measured phase current and flags this code when the Z-phase current exceeds the calibrated threshold, pointing to a short, a failing inverter, or a wiring fault.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the hybrid or electric vehicle warning light, often with a reduced power message
The vehicle may enter limp mode or refuse to start in ready mode
A noticeable loss of propulsion power or shuddering under acceleration
Audible whining or clicking from the inverter or motor area during operation
Often no symptoms besides the warning light if the fault is intermittent
Possible high-voltage system shutdown with a service vehicle soon message

Common causes, most likely first

Damaged or shorted phase Z cable between the inverter and the drive motor
Internal short or insulation breakdown in the drive motor A phase Z winding
Failed current sensor or signal circuit inside the inverter controller
Faulty inverter power module causing uncontrolled current flow in phase Z
Corroded or loose high-voltage connector pins at the motor or inverter
Coolant contamination or overheating of the inverter leading to component failure
Software calibration error in the inverter control module (rare but possible)

How to diagnose and fix it

Scan all modules for stored and pending codes, then record freeze-frame data for P2C71
Visually inspect the high-voltage phase cables and connectors for chafing, corrosion, or loose pins
Measure insulation resistance and continuity of the phase Z cable between inverter and motor
Check the motor phase Z winding resistance and compare it to the other two phases
Verify the inverter current sensor signal with a scope or manufacturer-specific live data
Perform any available inverter software update or recalibration before replacing hardware
Replace the faulty inverter, motor, or cable only after electrical tests confirm the failed component

Phase Z current faults that fool technicians

A loose high-voltage connector pin can mimic a failed inverter by causing intermittent phase Z current spikes that clear when the connector is reseated.
Coolant leaks into the inverter housing often damage only the current sensor circuit, setting P2C71 without any motor winding fault.
The code can be stored by a brief overcurrent event during hard acceleration and may never return, so always check for a recent software update before condemning parts.
Phase Z is one of three motor phases, and a single shorted winding can still allow the vehicle to move slowly, leading owners to delay repair until the inverter is also damaged.
A failing 12-volt battery or poor chassis ground can cause erratic current sensor readings that set this code, so verify supply voltage and grounds first.

Can I keep driving with P2C71?

Do not continue driving with P2C71 active because a phase current fault can escalate to a high-voltage inverter failure or sudden loss of propulsion. Have the vehicle towed to a qualified hybrid or electric vehicle technician if it will not enter ready mode or shows reduced power.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.