Powertrain, generic (extended)

P27BB Pressure Control Solenoid N Electrical

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27BB is a catch-all electrical code for pressure control solenoid N, and no manufacturer documents it publicly. The two makers known to use solenoid N, GM on the Corvette dual-clutch unit (23OBDG07) and Ford on the TR9070, both split electrical faults of this synchronizer valve into separate codes instead: P27BD covers an open load, P27BF a grounded line and P27C0 a line shorted to battery voltage. A controller with a less detailed driver stage could report all of these under P27BB. CARB 13 CCR 1968.2 requires circuit monitoring of such output components. Checks therefore cover coil resistance, connector pins inside the transmission and the harness to the TCM.

Likely causes

Solenoid N coil open or shorted
Corroded or loose internal transmission connector
Damaged harness between TCM and transmission
Faulty output driver in the TCM

Symptoms

  • MIL on
  • Gears served by solenoid N unavailable

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

P27BCP27BDP27BFP27C0P08C6

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