P085E Gear Shift Control Module B Performance

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. P085E is the plausibility fault of module B, a second module or channel of the shift-by-wire system: communication works, but data are implausible or the module reports an internal fault. No maker documents it; Audi's P085D shows the same logic for module A.

Likely causes

Symptoms

• Selector or gearbox warning in the instrument cluster
• Range cannot be selected or only with delay, car stays in P/N
• Gearbox limp mode

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.