P2C6E — Drive Motor “A” Phase Y Current High

Diagnostic algorithm

1. Safety first: follow high-voltage safety procedures, wear HV PPE, and discharge HV capacitors before inspection
2. Retrieve and record full fault history, freeze frame, and live phase current values from the HV inverter/controller
3. Attempt to reproduce: perform controlled drive at low speed to see if fault reappears while monitoring phase currents with a current clamp or oscilloscope (use HV-rated sensors or measure at current-sensor outputs/CAN if available)
4. Visual inspection: examine all HV harnesses, connectors, and motor/inverter for damage, overheating, or contamination. Repair obvious wiring/connectors first.
5. Check current sensor: verify sensor supply and output signals (voltage or CAN). Compare sensor output to measured clamp meter current. Replace or repair sensor/harness if inconsistent.
6. Measure continuity and resistance: with HV disconnected and capacitors discharged, measure phase-to-phase resistances and compare across phases. Look for significantly lower resistance or asymmetry on Y phase.
7. Insulation test: perform megohm test between each phase and vehicle ground (motor body) to detect shorts to ground.
8. Inverter power devices: test diodes/IGBTs per service manual (diode/IGBT checks, manufacturer self-tests). A shorted transistor can cause single-phase overcurrent.
9. Bench motor test: if possible, test motor on a suitable dynamometer or swap motor to confirm motor vs. inverter fault.
10. Inspect drivetrain: rotate motor/driveshaft by hand to detect binding or mechanical resistance that could raise current.
11. Software/firmware: verify controller firmware and calibrations are up to date; clear codes and re-test after repairs.
12. Document findings and do not reapply HV until repairs follow manufacturer procedures.