Powertrain, generic (extended)

P2842 Shift Fork D Position Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2842 sets when the fork D sensor signal collapses toward zero. GM's 2023 Corvette table expects a pulse train from the rod 4 sensor and flags the circuit if pulses vanish with less than 2.0 V present, or if the duty cycle is lower than 8 %, both held for 150 ms; the resulting fault is Type A. In Ford's TR9070 summary the matching rod sensor 4 entry covers a too-narrow pulse and an input frozen at zero. Mercedes-Benz uses P284200 on the 8G-DCT for a fork D sensor shorted to ground. Since a missing sensor feed produces the same low picture, measure the 5 V supply at the connector first; on the Corvette that feed is shared with rod 3, so a combined P283D points to the supply rather than to one sensor.

Likely causes

Fork D signal wire shorted to ground or housing
No 5 V feed reaching the sensor
Fork D sensor internally failed

Symptoms

  • Warning lamp, fork D gears blocked
  • Transmission in emergency program
  • Additional fork C code if the shared feed is at fault

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 dshift fork position sensor dwiring harness

Related codes

P2843P2840P2844P2841P283D

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