This code indicates the brake booster’s three-phase electric motor (designated Motor B) is operating outside expected electrical parameters. The control module has detected an anomaly in the phase U, V, or W circuits—such as incorrect resistance, current imbalance, or open/short conditions—preventing proper motor performance.
Internal open or shorted windings within the three-phase motor create imbalanced resistance or current draw across the U, V, and W phases, causing the control module to detect a range/performance error.
Opens, shorts-to-ground, shorts-to-voltage, or high-resistance conditions in the phase circuits between the control module and motor disrupt the precise electrical signals required for motor commutation.
Poor terminal contact, spread pins, or corrosion at the motor or control module connector interrupts current flow in one or more phases, leading to performance faults.
The dedicated module driving the three-phase motor may have a failed internal driver circuit, power stage fault, or current-sensing error that incorrectly reports or causes a phase circuit malfunction.
High resistance, voltage drop, or open circuits in the motor or module power feeds and ground paths can cause erratic phase current readings and set performance codes.
In the rare instance where the PCM directly commands the booster motor, internal driver failure or corrupted software can set this code; this is the least likely cause and should only be considered after verifying all motor, wiring, and dedicated control module integrity.
No. This fault indicates a failure in the electric brake booster motor that provides power assist. Expect a very hard brake pedal and significantly longer stopping distances, making the vehicle unsafe to operate until repaired.
Usually yes. The three-phase motor is typically integrated into the brake booster unit and is not serviced separately. If the motor windings or internal sensors are faulty, replacement of the complete booster assembly is the standard repair.
Rarely. While the PCM or a dedicated brake control module monitors the circuit, the root cause is almost always the motor itself, wiring damage, or the dedicated motor driver module. Replacing the PCM is usually not the fix and should only be done after exhaustive testing of the motor and circuits.
'Motor B' designates a specific motor circuit identifier within the brake system architecture, often indicating a secondary booster motor, a redundant system channel, or a specific motor designation in vehicles with complex brake-by-wire or dual-booster configurations.