Powertrain, generic (extended)

P2865 Shift Fork E Position Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2865 means the fork E position input is stuck low. On GM's 2023 Corvette, whose rod 5 sensor sends a pulse-width signal, the TCM runs two Type A checks under this number: no pulses at all while the pin rests below 2000 mV, or a duty cycle under 8 %, each confirmed after 150 ms. The test is suspended while cranking, outside 8.75 to 18 V battery voltage, or when the sensor reference supply leaves its band. Mercedes-Benz names P286500 on the 8G-DCT plainly as a short to ground of the fork E position sensor. Look for a signal wire grounded in the harness, a sensor with an internal short, or a missing reference voltage. The high-side counterpart is P2866, the frequency fault P2867.

Likely causes

Fork E sensor signal wire shorted to ground
Fork E sensor with internal short or failed output stage
Sensor supply missing because of an open feed

Symptoms

  • Warning lamp with fork E gears blocked
  • Fault returns at once after clearing

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time0.5–8 h

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

Parts involved

shift fork eshift fork position sensor ewiring harness

Related codes

P2866P2863P2867P2864P2842

References: gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.