Powertrain, generic (extended)

P283C Shift Fork C Position Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P283C is the plausibility code for fork C, which GM's 2023 Corvette table assigns to rod 3 on the even-gear shaft. Besides the force and speed comparison during shifts (over 600 N, more than 1100 µm off the learned point, Type A), a static monitor runs here: with no shift force on the rod, the reading must stay inside tolerance bands around the learned neutral or engaged point. A drift is only confirmed once clutch speed can be checked against engine speed and output speed against the driven wheels. A confirmed fault triggers recovery of the even shaft synchronizer. Ford's TR9070 uses P283C for rod sensor 3 consistency and logs drift separately as P277E, while Mercedes-Benz describes it as a malfunction of the fork C sensor on the 8G-DCT.

Likely causes

Rod 3 creeping out of position because of worn detent or fork
Position values not relearned after gearbox or sensor work
Synchronizer actuation on the even shaft not reaching target position

Symptoms

  • Even gears drop out or refuse to engage
  • Grinding or a knock during shifts on the even shaft
  • Warning lamp, gearbox limits gear choice

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–3,500
Time1–10 h

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

Parts involved

shift fork cshift fork position sensor cwiring harness

Related codes

P283BP283DP283EP283FP2847P2837

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