Powertrain, generic (extended)

P27C8 Pressure Control Solenoid P Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27C8 signals too high a level in the control circuit of solenoid P. GM's Corvette DCT tables 23OBDG07 and 24OBDG07 store it for synchronizer actuation valve 3 in three situations, all Type A. First, with the low-side switch on, the sense voltage stays above a supply-dependent limit of 0.7, 0.9 or 1.1 V (below 11.5 V, 12-15 V, above 15.5 V battery). Second, the current estimated from duty cycle and supply deviates from its target by more than 70 % (60 ms) or by more than 400 mA (300 ms). Third, a shutdown routine switches each output separately, detects valve 3 shorted to a neighbour and sets the code at the next start. Ford calls it shorted load on SPV3 of the TR9070.

Likely causes

Control line shorted to battery voltage
Control line shorted to a neighbouring solenoid output
Solenoid P coil with too low resistance (shorted turns)
TCM driver stage fault

Symptoms

  • MIL on, possibly at the start after a previous drive
  • Gears of rods 3/4 unavailable
  • 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 pwiring harness

Related codes

P27C7P27C5P27C6P27C3P27D0P27C0

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