Damaged or chafed phase cable between the inverter and motor; Loose or corroded terminal at the motor or inverter connector; Failed current or voltage sensor inside the inverter; Internal short or open in the motor stator winding; Faulty inverter power module or gate driver board; Water intrusion or contamination in the motor or inverter housing; Software calibration error in the motor control module

DTC codes / P0Cxx · Hybrid propulsion / P0C06

P0C06Drive Motor A Phase U-V-W Circuit Low

Q: What does code P0C06 mean?

Drive Motor A Phase U-V-W Circuit Low. P0C06 indicates that the inverter or motor control module has detected an abnormally low voltage or current on the phase U, V, or W circuit of drive motor A, which is the primary traction motor in a hybrid or electric vehicle. The computer compares commanded phase output against measured feedback and flags the circuit as low when the signal falls outside the expected range under load.

P0C06 indicates that the inverter or motor control module has detected an abnormally low voltage or current on the phase U, V, or W circuit of drive motor A, which is the primary traction motor in a hybrid or electric vehicle. The computer compares commanded phase output against measured feedback and flags the circuit as low when the signal falls outside the expected range under load.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or hybrid/EV system warning lamp
Reduced power or limp-home mode with limited motor output
The vehicle may refuse to start or shift into drive
Audible whining or clicking from the inverter area under acceleration
Intermittent stalling or sudden loss of propulsion while driving
Often no symptoms besides the warning light if the fault is intermittent

Common causes, most likely first

Damaged or chafed phase cable between the inverter and motor
Loose or corroded terminal at the motor or inverter connector
Failed current or voltage sensor inside the inverter
Internal short or open in the motor stator winding
Faulty inverter power module or gate driver board
Water intrusion or contamination in the motor or inverter housing
Software calibration error in the motor control module

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm when the low phase condition occurs
Visually inspect the phase U, V, and W cables and connectors for chafing, corrosion, or loose pins
Measure resistance and insulation between each phase and ground at the motor terminals
Perform a voltage drop test on the phase cables under load if accessible
Check the inverter for stored history codes and verify sensor feedback with a bidirectional scan tool
Replace the faulty phase cable or connector if damage is found
If the motor or inverter is internally faulty, replace or repair the affected assembly per manufacturer procedure

Phase cable damage often mimics inverter failure

A chafed phase cable rubbing against a chassis ground can set P0C06 without any internal inverter fault, so always inspect the harness routing before condemning the inverter.
Intermittent low-phase codes often appear only during high-load acceleration or regenerative braking, so a static resistance test may pass while the fault is still present.
Some manufacturers require a software update to the motor control module to correct false low-phase detection before any hardware replacement is attempted.
Water intrusion into the motor connector can create a partial short that reads as a low phase circuit, especially after car washes or heavy rain.
The code does not always mean the motor is failing; a failed current sensor inside the inverter can report low phase current while the motor and cables are healthy.

Can I keep driving with P0C06?

Do not continue driving with this code active because a low phase circuit can cause sudden loss of propulsion or further damage to the inverter and motor. Have the vehicle towed to a qualified hybrid/EV technician for diagnosis.

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.