C05AE: ABS Pump Motor Calibration Not Learned

What it means

ABS pump motor calibration values not learned — required after pump or HCU replacement.

At a glance

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

How it works

The ABS control module stores learned calibration values for the pump motor so it can control the pump correctly. This code sets when those values have not been learned or are unavailable, often after pump or hydraulic control unit replacement, interrupted setup, or low voltage during calibration.

Common causes

Most likely first.

1. ABS pump motor calibration or initialization not completed
2. Calibration procedure interrupted or performed incorrectly
3. ABS hydraulic control unit or pump motor replaced without setup
4. Low system voltage during calibration

Symptoms

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

How to diagnose it

1. Save freeze-frame data and check for low-voltage or ABS setup codes that may explain why the pump calibration was not learned.
2. Check battery and charging system condition and verify stable voltage against the manufacturer's specification.
3. Confirm whether the ABS pump motor or hydraulic control unit was recently replaced and whether the required setup was completed.
4. Inspect pump wiring and connectors for faults that could interrupt calibration or prevent the module from recognizing the motor.
5. Perform the manufacturer's pump motor calibration procedure with the vehicle conditions and tools it specifies, then confirm the code does not return.

Common fixes

• Restore battery or charging system voltage if it is too low or unstable.
• Repair pump wiring or connector faults that interrupt the setup process.
• Complete the required pump motor calibration or initialization procedure.
• Recheck replacement pump or hydraulic control unit compatibility and installation if calibration will not complete.

Can I keep driving?

ABS and stability control may remain disabled, and brake assist may be reduced. Have the calibration completed before relying on these functions; avoid driving if braking feels abnormal.