Chassis, generic

C0559 Power Steering Control Module Range/Performance – Rear

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0559 covers the rear steering controller, the electronics of active rear-wheel steering, when it fails its own performance or plausibility checks. Systems such as ZF's AKC turn the rear wheels by up to 12° opposite to the front ones at low speed and in the same direction from about 60 km/h. No maker documents C0559 publicly, but the faults are known under other codes: Bentley logs P060700 (control module performance) in the rear axle steering unit J1019 and checks damage, ground point 710, replaces the rack and realigns; Audi updates J1019 software for C12A329 and asks for an alignment; on the 2017 Q7 a sensor signal discrepancy lit the steering lamp. A Mazda patent compares three position detectors, uses the agreeing pair and returns the wheels to centre. The car then drives like one without rear steering.

Likely causes

Rear steering control module software fault (update available)
Disagreeing position or angle signals inside the rear steering actuator
Poor ground or supply of the rear steering unit
Damaged, contaminated or worn rear steering actuator

Symptoms

  • Steering or rear steering warning in the instrument cluster
  • Larger turning circle, rear wheels held straight
  • Driver assistance functions limited on some models

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rear eps module

Related codes

C059AC0450U0134U0435

References: zf.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.