Powertrain, generic (extended)

P281D Pressure Control Solenoid H Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P281D signals that the control line of solenoid H is shorted to ground. In GM's 2016 eight-speed table H is the on/off default valve; the low flag must persist for 0.3 s within 0.5 s and one trip lights the MIL. The 2020 tables extend this to the nine- and ten-speed converter clutch valve, using about 0.5 ohm to ground as the limit and rating it Type A, and add that T87a eight-speed controllers also report an open default valve circuit as P281D, so an interrupted wire can hide behind this code. On the 2023 Corvette dual-clutch box the redundant shutdown valve of the differential is checked while switched on; a voltage below about 1.7 V at the output pin is held for 150 ms before the Type B code is stored.

Likely causes

Control wire of solenoid H shorted to ground
Open default valve circuit reported as low (GM T87a eight-speed)
Coil insulation failure inside solenoid H

Symptoms

  • MIL on after a single trip
  • Transmission in default gear or fixed pressure mode
  • Converter lockup or differential lock unavailable

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

P281EP281BP2819P2814P2818

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.