Powertrain, generic (extended)

P27C0 Pressure Control Solenoid N Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27C0 reports too high a voltage on the control line of solenoid N, usually a short to battery or to a neighbouring output. On the Corvette with GM's dual-clutch gearbox (table 23OBDG07, 2023), synchronizer actuation valve 2 is flagged when the sense voltage stays above roughly 0.7 to 1.1 V, depending on supply voltage, while the low-side switch is on, or when actual current misses the target by over 70 % for 60 ms or by over 400 mA for 300 ms. A separate test at shutdown energizes the outputs one by one to find two lines shorted together, stores the result and sets P27C0 at the next start. All are Type A; 24OBDG07 keeps the code. Ford's TR9070 list names it shorted load on SPV2.

Likely causes

Control wire shorted to a supply voltage
Two solenoid lines shorted together in the harness or connector
Partially shorted solenoid coil drawing wrong current
Damaged output stage in the TCM

Symptoms

  • MIL on
  • Shift rod cannot be actuated; gears missing
  • Code returns at every start after a shutdown test

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 nwiring harness

Related codes

P27BFP27BDP27BEP27BBP08CBP27C8

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