Powertrain, generic (extended)

P27C1 Pressure Control Solenoid P Performance/Stuck Off

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27C1 is logged when pressure control solenoid P is commanded but the shift rods it serves barely move. In GM's Corvette dual-clutch documentation (23OBDG07, unchanged in 24OBDG07) the part is shift solenoid 3; with the selector valve in one position it pushes rod 3, in the other rod 4, both in the A-to-B direction. During GM's intrusive synchronizer check, run after a shift fault or a gear mismatch found at power-up, travel of 100 µm or less on the commanded rod counts as no response, Type A. Ford's 2024 summary assigns the code to SPV3 of the TR9070. Gears selected via rods 3 and 4 may be locked out and the gearbox may run on a reduced set of ratios.

Likely causes

Valve spool of solenoid P held in the closed position by debris or varnish
Low, aerated or degraded transmission fluid so no pressure builds
Leaking seal on the shift rod actuator piston for rods 3/4
Mechanically binding shift rod or fork

Symptoms

  • MIL on with transmission warning
  • Certain gears skipped or not selectable
  • Delayed or failed launch in affected gear

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–2,500
Time2–8 h

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

Parts involved

pressure control solenoid pvalve body

Related codes

P27C2P27C5P27C9P27D1P27B9P08C4

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