P0C03: Drive Motor B Current Low

What it means

The total current draw of drive motor B reports a current low fault. Motor operation may be impaired.

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 inverter monitors the motor's total current while controlling propulsion and regenerative braking. P0C03 sets when reported current is lower than expected for the operating conditions, which may reflect unusually low motor load or a current sensor that has drifted low.

Common causes

Most likely first.

1. Motor load lower than expected
2. Current sensor offset drifted low

Symptoms

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

How to diagnose it

1. Check freeze-frame and live data for Drive Motor B current alongside requested torque, speed, and operating mode to see whether the low reading matches the actual demand.
2. Look for related Drive Motor B, inverter, or sensor codes that could explain a current calculation problem.
3. With the vehicle powered down under its service instructions, inspect the Drive Motor B current-sensor connections and harness for loose, damaged, or corroded areas.
4. Have a technician compare Drive Motor B's reported current with commanded operation using the manufacturer's diagnostic procedure.
5. Test the current sensor and its circuit against the manufacturer's specification to confirm whether the reading is biased low.

Common fixes

• Repair a loose or corroded current-sensor connection.
• Repair damaged wiring in the Drive Motor B current-sensing circuit.
• Replace the sensor if testing confirms low offset drift.
• Repair the inverter or motor only if further tests identify a fault.

Can I keep driving?

Use moderate acceleration and avoid relying on full Drive Motor B power, since the vehicle may limit torque or enter limp mode. Stop safely if propulsion weakens unexpectedly or a shutdown warning appears.