Powertrain, generic · Transmission

P073E Unable to Engage Reverse

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P073E means reverse is commanded but not reached. Two uses are documented. With electronic gear selection (shift-by-wire) GM compares the commanded range with the actual range reported by the transmission and flags it if reverse is not reached within 1.8–3 s in the selector or diesel engine module, or 10 s in petrol engine modules, after two trips; GM bulletins name a range actuator centred wrongly (LaCrosse, XT5) and software after an over-the-air update (2025 Equinox/Terrain). On dual-clutch transmissions (2020–23 Corvette, Maserati MC20) it means the reverse gear cannot be engaged. Stuck in reverse is P072B, slip in reverse P0736.

Likely causes

Range actuator or park module centred wrongly or faulty (shift-by-wire)
Module software (e.g. after an over-the-air update)
Range sensor reports the wrong actual range
Reverse clutch or brake, valve or shift fork (DCT)
Fluid level or system pressure

Symptoms

  • No reverse, or R not accepted
  • Transmission warning, check engine light after two trips (GM)
  • Display shows R but the vehicle does not reverse

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–5,000
Time0–12 h

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

Parts involved

transmission range selectortransmission range sensorshift fork actuatortransmission control module

Related codes

P073DP072BP0736P0705P07E4

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.