Powertrain, generic · Hybrid propulsion

P0C29 Electric/Auxiliary Transmission Fluid Pump A Driver Circuit Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C29 means the driver stage of auxiliary pump A does not behave as commanded, for instance the pump does not reach its target or the activation is reported as implausible. Volkswagen Group documents it on the 7-speed DSG 0GC (DQ381): VW lists P0C29 for the 2018 Golf R as implausible activation of auxiliary hydraulic pump 1 (V475), often with clutch and gear actuator codes as consequences; Audi's bulletin for the 2017-18 A3, A3 Cabriolet and S3 with gearbox dated up to 26 September 2017 calls for replacing the auxiliary hydraulic pump when only P0C29 remains. The customer sees a Gearbox Malfunction warning. VW improved the pump from October 2017 production. P0C2A is a stalled motor, P0C26 to P0C28 current faults.

Likely causes

Auxiliary hydraulic pump V475 of early production faulty (VW/Audi 0GC)
Poor contact at the pump electrical connection
Transmission control software not updated per service action

Symptoms

  • Gearbox Malfunction warning in the instrument cluster
  • Consequential clutch or gear actuator codes, limp mode

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€400–2,500
Time2–8 h

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

Parts involved

aux trans pump a driver

Related codes

P0C2AP0C26P0C27P0C28P2797

References: static.nhtsa.gov, static.nhtsa.gov.