Powertrain, generic (extended)

P27D4 Pressure Control Solenoid S Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27D4 means the controller noticed solenoid S dropping out now and then, electrically or in its effect, without the fault staying present. No manufacturer publishes this code. GM, whose Corvette dual-clutch gearbox has a fifth synchronizer valve for rod 5 (tables 23OBDG07 and 24OBDG07), reports lasting wiring faults on it as P27D5, P27D7 and P27D8 and its stuck states as P27D1 and P27D2; a separate sporadic code is not listed there. CARB 13 CCR 1968.2 still requires transmission actuators to be monitored. For the driver it can mean an occasional refusal of the rod 5 gears. Wiggle-test the harness with the engine running, inspect the gearbox connector seal and check whether the fault follows heat.

Likely causes

Gearbox connector seal leaking, terminals corroding
Harness conductor breaking under engine movement
Solenoid S winding dropping out when hot

Symptoms

  • MIL comes and goes
  • Rod 5 gears occasionally refused

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–800
Time1–4 h

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

Parts involved

pressure control solenoid swiring harness

Related codes

P27D3P27D5P27D7P27D8P27D1P27CC

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com.