Code
P0C0C
Generic
P — Powertrain
Drive Motor A Inverter Power Supply Circuit Low
Views:
UK: 22
EN: 40
RU: 28
AI status
Completed
Completed
100%
Causes
- Blown fuse or tripped relay in inverter control supply circuit
- Loose, corroded or damaged inverter connector or wiring
- Low 12 V battery or weak auxiliary battery
- HV DC link / precharge failure preventing inverter supply
- Internal inverter power supply or regulator failure
- Poor ground or high-resistance ground connection
Symptoms
- Inverter or drive system warning lamp and DTC P0C0C stored
- Reduced propulsion power or limp-home mode
- No drive motor operation even when other systems appear normal
- Multiple related HV or BMS warnings
- Possible loss of charging or regen capability
- Intermittent faults that may clear after key cycle
What to check
- Read all stored DTCs and freeze frame / snapshot data; note conditions when code set
- Verify state of charge (SoC) and voltages of the high-voltage battery pack and 12 V auxiliary battery
- Visually inspect inverter connectors, wiring harness, fuses and relays for damage, corrosion or overheating
- Check continuity and voltage at inverter control supply pin(s) with key ON (use insulated HV-safe procedures)
- Confirm proper operation of HV contactors/precharge circuit and DC link voltage present at inverter
- Measure ground resistance between inverter ground and chassis (expect very low resistance)
Signal parameters
- Inverter control (logic) supply: typically ~12 V when key/IG ON (manufacturer spec e.g., ~11–14 V) — check vehicle-specific value
- HV DC bus / inverter DC link: should match HV battery pack nominal voltage (varies by vehicle) and be within manufacturer tolerance
- Ground continuity: very low resistance (
- Fuse/relay supply presence: battery/ignition feed present at fuse/relay input and output with key on
- CAN/comm status: valid CAN frames to/from inverter control module
Diagnostic algorithm
- Safety first: follow manufacturer high-voltage safety procedures. Disable HV system and remove service disconnect if required before any physical inspection.
- Scan and record all DTCs, freeze frame data, and live data. Note exact voltages and conditions when the code stored.
- Check auxiliary 12 V battery state and charging system. Replace or charge if low; recheck code.
- With appropriate precautions, inspect inverter power/ground connectors, fuses, and relays. Repair any corrosion, loose pins or damage.
- With vehicle in a safe, energized test state and using HV-rated tools, measure voltage at the inverter control supply pin(s) with key ON. Compare to expected values.
- Verify DC link voltage at inverter input. If DC link is missing or low, inspect HV contactors, precharge resistor/circuit and main fuse.
- Check ground continuity to chassis and battery negative. Repair any high-resistance connections.
- If wiring, fuses, relays and batteries check good but supply remains low, suspect internal inverter regulator or controller fault — consult manufacturer technical service information.
- If repairs made, clear codes, perform functional tests and road test. If DTC returns, capture new data and escalate to inverter/module replacement per OEM procedures.
- If isolation/insulation tests indicate HV leakage or isolation fault, address HV battery/insulation issues before inverter replacement.
Likely causes
- Faulty or open fuse/relay feeding the inverter control supply
- Loose/damaged wiring or connector at the inverter (control supply pins)
- Weak 12 V auxiliary battery or low accessory battery voltage
- Internal inverter electronics (power regulator) failure
- High-voltage contactor/precharge not engaging, so DC bus is low
Fault status
Status
Drive Motor A inverter control/logic supply voltage detected below threshold. Inverter may be disabled or limited — repairs to supply circuit, fuses, connectors, battery or inverter module required.
Repair difficulty: Hard
Diagnostic time: 1.0-4.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email