Powertrain, generic (extended)

P27BC Pressure Control Solenoid N Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P27BC reports that the signal or response of pressure control solenoid N drops out now and then rather than failing permanently. No manufacturer documents this code publicly; the GM and Ford dual-clutch documents that use solenoid N for the second synchronizer valve (23OBDG07, Ford TR9070 list) only publish its permanent electrical and hydraulic faults. CARB 13 CCR 1968.2 counts automatic transmission solenoids among the outputs whose circuits must be watched for faults. Loose terminals, a chafed wire that touches only under vibration or heat, or a coil that opens when hot are the usual suspects. Because the fault comes and goes, freeze-frame data and a wiggle test with the harness moved are more useful than a single static measurement.

Likely causes

Loose or spread terminal at solenoid N or TCM
Chafed wire shorting under vibration
Coil opening intermittently when hot

Symptoms

  • MIL that comes and goes
  • Occasional missed or delayed shifts

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–800
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

P27BBP27BDP27BFP27C0P08C7

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