P0C4F: Drive Motor B Position Exceeded Learning Limit

What it means

The control module compares the learned position of drive motor B with its allowed range. It sets this code when the learned position falls outside that range.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Drive motor B's position sensor provides rotor-position information that the hybrid or EV control module uses to control motor torque. The module checks the learned position against its allowed range and sets P0C4F when motor B's position cannot be learned within that limit.

Common causes

Most likely first.

1. Position sensor or its circuit fault
2. Drive motor position or alignment outside the expected range

Symptoms

• EV/hybrid system warning light on
• Reduced motor power or torque
• Possible limp mode or vehicle shutdown

How to diagnose it

1. Save freeze-frame data and check for related motor B, position-sensor, inverter, or hybrid-system codes before clearing anything.
2. Review scan-tool data for drive motor B position and learning status for missing, unstable, or out-of-range readings.
3. With the vehicle powered down according to the manufacturer's high-voltage safety procedure, inspect accessible motor B position-sensor connectors and wiring for damage or poor connections.
4. Test the motor B position-sensor circuit using the manufacturer's wiring diagram and procedure, including continuity and signal integrity.
5. If the sensor circuit passes, check motor B position and alignment and carry out only the manufacturer's specified learning procedure.

Common fixes

• Reconnect or secure a loose motor B position-sensor connector.
• Repair damaged motor B sensor wiring or terminals.
• Replace the motor B position sensor if it fails the specified tests.
• Correct a confirmed motor B position or alignment issue and perform the manufacturer's learning procedure.

Can I keep driving?

Reduced motor torque, limp mode, or shutdown may occur, so avoid high-speed trips and heavy loads. If the vehicle warns of a hybrid-system fault or loses power, stop safely; high-voltage system diagnosis requires appropriate training.