C058F: Regeneration Torque Performance

What it means

Regenerative braking torque does not match commanded value — affects brake blending on EVs/hybrids.

At a glance

• Usually lights the ABS or stability-control warning light
• The engine or gearbox may go into limp mode

How it works

In a hybrid or electric vehicle, regenerative braking uses the drive motor to slow the vehicle and coordinates with friction brakes to meet the driver's requested braking. The brake control module compares measured regenerative torque with the commanded amount; C058F sets when delivered torque does not perform as expected, potentially disrupting brake blending and related stability functions.

Common causes

Most likely first.

1. Regenerative braking system fault
2. Brake blending control or communication fault
3. Brake system sensor or wiring fault
4. Control module fault

Symptoms

• ABS warning light on
• ESC/stability control deactivated
• Possible reduced brake assist
• Speedometer may behave erratically

How to diagnose it

1. Record freeze-frame data and review regenerative torque command and feedback, vehicle speed, and related brake or stability codes to identify when the mismatch occurred.
2. Check whether the ABS or stability warning is accompanied by erratic speed readings, and inspect the relevant wheel-speed sensors and wiring for visible damage.
3. Inspect accessible regenerative braking, brake blending, and communication wiring and connectors for looseness, corrosion, or damage.
4. Use a capable scan tool to compare regenerative torque request and response during the conditions in the freeze-frame, following the manufacturer's safety procedures.
5. If sensor inputs and wiring are sound, check module communication and run the manufacturer's diagnostic tests for the regenerative braking and brake blending controls.

Common fixes

• Repair damaged wiring or connector faults affecting regenerative braking or brake blending signals.
• Repair a faulty wheel-speed or brake-system sensor identified by testing.
• Correct a communication fault between the brake and regenerative torque control systems.
• Repair or replace a control module only after its inputs, wiring, and communication paths are verified.

Can I keep driving?

Braking behavior may change because regenerative and friction braking may not blend normally, and stability control may be unavailable. Avoid high speeds and slippery roads; stop safely and arrange service promptly if braking feels inconsistent or reduced.