Powertrain, generic (extended)

P281A Pressure Control Solenoid H Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P281A marks a fault at valve H that comes and goes, either electrically or in its hydraulic effect. There is no public manufacturer description of P281A. CARB 13 CCR 1968.2 calls for monitoring of such actuators but does not prescribe an intermittent code. GM's 2020 tables show why short dropouts are hard to catch: the H circuit codes P281B, P281D and P281E only set when a fault flag stays active for at least 0.3 of every 0.5 s, so a contact that opens for a few milliseconds may only show up as a rough shift. Typical places for such faults are loose terminals at the gearbox connector, cracked solder joints in a mechatronic unit and coils that fail only when hot. Freeze-frame data and a wiggle test with live data help more than a single resistance check.

Likely causes

Loose or corroded terminal at the transmission connector
Coil of valve H failing only at operating temperature
Cracked solder joint in an integrated mechatronic unit

Symptoms

  • Occasional harsh or delayed shift
  • Warning lamp that comes and goes
  • Short spells of limp-home mode

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–2,500
Time1–6 h

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

Parts involved

pressure control solenoid hwiring harness

Related codes

P2819P281BP281DP281EP2811

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