P281APressure Control Solenoid H Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Occasional harsh or delayed shift
- Warning lamp that comes and goes
- Short spells of limp-home mode
- Likely causes
- LikelyLoose or corroded terminal at the transmission connector
- PossibleCoil of valve H failing only at operating temperature
- RareCracked solder joint in an integrated mechatronic unit
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.