Powertrain, generic (extended)

P283D Shift Fork C Position Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P283D reports the fork C input stuck low. In the Corvette dual-clutch gearbox GM feeds the rod 3 sensor from reference B rather than reference A, so its enable test watches that second 5 V rail and pauses while P0652 or P0653 are present. Within those limits the code sets after 150 ms if no pulses are seen and the pin stays below 2.0 V, or if the duty cycle falls under 8 %; it is classed Type A. For rod sensor 3 of the TR9070, Ford reports a zero-stuck input whose pulse width falls short of the window. Mercedes-Benz interprets P283D00 on the 8G-DCT as a fork C sensor shorted to ground. Because rods 3 and 4 share reference B on the Corvette, a supply fault there would also disturb fork D.

Likely causes

Fork C signal line shorted to ground in the gearbox harness
Fork C sensor no longer switching its output
Damaged supply wire from reference B to the sensor

Symptoms

  • Limp-home mode with warning lamp
  • Gears of fork C unavailable
  • Possibly further fork D codes if the shared supply is affected

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1–6 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

P283EP283BP283FP283CP2842P0652

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