P0C58

What it means

P0C58 means the hybrid or electric vehicle control unit has seen the signal from the position sensor on drive motor B (the sensor that reports rotor angle and speed, often a resolver or encoder) read higher than its expected range on circuit A. Accurate rotor position is needed to control the motor properly, so the system treats this as a fault. Which wire or channel 'circuit A' refers to depends on the model and sensor design.

Symptoms

• Hybrid or EV system warning light on, often with the main warning lamp
• Reduced power or limp-home mode
• Vehicle will not enter Ready mode or will not move
• Rough, jerky or cutting-out drive from the electric motor
• Engine starting more often or running more than normal on a hybrid
• Other drive motor or inverter fault codes stored alongside

Possible causes

• Damaged, chafed or shorted wiring in the motor position sensor circuit (short to voltage or an open circuit that pulls the signal high)likely
• Corroded, loose or water-contaminated connector at the motor, inverter or control unitlikely
• Faulty drive motor position sensor (resolver or encoder)possible
• Fault in the inverter or motor control unit's sensor interface or reference supplypossible
• Electrical interference or poor shielding or earthing of the sensor wiringrare
• Mechanical damage or misalignment of the sensor following motor or gearbox repairrare

How to diagnose

1. Read all stored codes and freeze frame data, noting vehicle state, speed and temperature when the fault set, and check for related motor or inverter codes
2. Check for technical service bulletins or known issues for the specific model and motor layout
3. Following the manufacturer's high-voltage safety procedure, and only if trained to do so, visually inspect the sensor wiring and connectors at the motor and inverter for chafing, coolant or water ingress, corrosion and bent or pushed-back pins
4. Check live data for the motor B position or speed signal and see whether it is stuck, erratic or out of range, and whether it changes when the harness is gently moved
5. Test the sensor circuit for short to voltage, open circuit and resistance between pins against the manufacturer's specification, with the system safely isolated
6. Measure the sensor's own resistance or coil values against the specification for that model
7. Check the sensor supply or excitation and the signal at the control unit end to separate a wiring fault from a unit fault
8. Clear the code after repair and road test, confirming it does not return

How to fix

• Repair or replace damaged wiring, with correct sealing and routing to prevent repeat chafing
• Clean, dry and repair or replace corroded or damaged connectors and terminals, and fix the source of any water ingress
• Replace the drive motor position sensor, then carry out any sensor alignment or learning procedure the manufacturer requires
• Repair or replace the inverter or motor control unit if testing shows the fault is internal, with any required programming
• Restore proper shielding and earth connections where interference is the cause

Can I keep driving?

Nearby codes

• P0C57GenericDrive Motor B Position Sensor Circuit A Low
• P0C59GenericDrive Motor B Position Sensor Circuit A Intermittent/Erratic