Powertrain, generic (extended)

P27D7 Pressure Control Solenoid S Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27D7 reports the control line of solenoid S stuck at too low a level, typically a short to ground. GM applies it to synchronizer actuation valve 5 on the Corvette dual-clutch gearbox (23OBDG07, carried into 24OBDG07): with the output switched on, the sense pin should be pulled down only partly; if it drops below roughly 1.7 V and stays there 150 ms, the driver chip flags a ground short and the TCM stores a Type A fault. As the coil is switched on the ground side, a grounded line can leave valve 5 powered without command, pushing rod 5 against the intended gear. Ford's TR9070 does not use solenoid S. Look for chafed insulation near brackets and for a coil shorted to its housing.

Likely causes

Control wire chafed through to ground
Solenoid S coil shorted to its housing
Faulty low-side driver in the TCM

Symptoms

  • MIL on
  • Unintended rod 5 movement, gears locked
  • Limp mode

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
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

P27D8P27D5P27D6P27D2P27CF

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