Calibration procedure was never performed after module replacement or reprogramming; Interrupted or failed calibration routine due to low battery voltage or communication dropout; Corrupted or erased calibration memory in the rear power steering control module; Software or firmware update applied without completing the required calibration step; Wiring or connector fault causing the module to lose power during a calibration attempt; Internal module fault preventing calibration data from being stored

DTC codes / C05xx · Brakes, steering and suspension / C059A

C059APower Steering Control Module - Rear Missing Calibration

Q: What does code C059A mean?

Power Steering Control Module - Rear Missing Calibration. C059A indicates that the rear power steering control module has not been calibrated, meaning the module lacks the learned zero-point or center position needed to command assist accurately. The module detected that its internal calibration memory is empty or invalid, so it cannot reliably translate steering angle and torque inputs into motor commands.

C059A indicates that the rear power steering control module has not been calibrated, meaning the module lacks the learned zero-point or center position needed to command assist accurately. The module detected that its internal calibration memory is empty or invalid, so it cannot reliably translate steering angle and torque inputs into motor commands.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaBrakes, steering and suspension

Symptoms you may notice

Power steering warning light illuminated on the dashboard
Heavier than normal steering effort, especially at low speeds
Steering assist that feels uneven or pulls to one side
A stability control or traction control warning light may also appear
Often no symptoms besides the warning light if the module defaults to a safe assist curve

Common causes, most likely first

Calibration procedure was never performed after module replacement or reprogramming
Interrupted or failed calibration routine due to low battery voltage or communication dropout
Corrupted or erased calibration memory in the rear power steering control module
Software or firmware update applied without completing the required calibration step
Wiring or connector fault causing the module to lose power during a calibration attempt
Internal module fault preventing calibration data from being stored

How to diagnose and fix it

Connect a scan tool and read all modules for related codes, especially in the power steering and stability control systems
Verify battery voltage and charging system health, as low voltage aborts calibration routines
Inspect the rear power steering module connectors and grounds for corrosion or looseness
Perform the manufacturer-specified calibration or zero-point reset procedure with a capable scan tool
Clear codes and cycle the ignition, then recheck for C059A and confirm calibration status
If calibration will not complete, check for software updates or module reprogramming per service information
Replace the rear power steering control module only after wiring and software causes are ruled out, then recalibrate

Why calibration fails and what it really means

A rear power steering module that has never been calibrated will often set C059A even though the hardware is perfectly functional, so replacement is frequently unnecessary.
Low battery voltage during a calibration attempt is one of the most common reasons the routine aborts and the code returns immediately after clearing.
Some vehicles require the calibration to be performed with the steering wheel held at a specific angle and the vehicle on level ground, and skipping that step stores the code again.
C059A can be set by a communication dropout on the controller area network (CAN) bus during calibration, which leaves the module without valid learned data.
A module that has been flashed with updated software may need calibration re-run even if it was calibrated before the update.

Can I keep driving with C059A?

You can usually drive the vehicle to a workshop, but expect heavier steering effort and reduced assist, so avoid high-speed maneuvers and tight parking situations until the calibration is completed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.