P085DGear Shift Control Module A Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Gear shift control modules A and B are selector modules of shift-by-wire systems, such as Audi's selector lever J587 or Stellantis' rotary shift module. The codes cover a dedicated link to the gearbox module and the module's plausibility. If the selected range cannot be transferred reliably, the gearbox holds its range, goes to P at standstill or into limp mode. Modules on CAN report lost communication as U0103 or invalid data as U0404 instead; GM uses its own codes. P085D means communication works, but the data or status of module A are implausible. Audi documents it on the 2019–21 A6/A7 family: the gearbox module stores P085D when the selector lever reports position sensor or P-button faults; drivers see a selector warning and cannot select a range. A software update of the lever fixes its over-sensitive voltage evaluation.
- What you may notice
- Selector lever fault shown in the cluster
- No range selectable, car stays in P
- Gearbox limp mode
- Likely causes
- LikelySelector module software (Audi update J587)
- PossibleSelector module faulty: position sensor, P button
- PossibleSupply voltage dips at the module
- RareConnector or wiring at the lever
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.