Powertrain, generic (extended)

P2728 Pressure Control Solenoid E Control Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2728 marks the circuit of solenoid E as working but not plausible. GM uses it in two ways. On the Allison 1000 (16OBDG08, 17OBDG04) the TCM compares desired with actual current on PCS 1; a gap of at least 0.5 A in 10 of fewer than 20 samples sets a Type A fault with MIL. On the T76 six-speed table of 2016, where valve E serves the 1-2-3-4 clutch, an invalid voltage flag for 4.4 of 5 s sets it without MIL. Bulletin PI0893 explains the second case for 2013 vehicles with the 6T70/6T75: as a Type C history code next to P2719 and P0965 it can appear falsely with fluid between -0.5 and 0 °C in Park or Neutral and needs no parts. MIL behaviour therefore depends on the gearbox.

Likely causes

Coil current deviating from command (resistance change, poor contact)
False history code near 0 °C fluid temperature (GM 6T70/6T75)
Unstable supply voltage to the TCM
Worn solenoid E

Symptoms

  • MIL on Allison-equipped trucks
  • History code without symptoms on GM six-speeds
  • Firm shifts if pressure control is degraded

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,200
Time0.3–5 h

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

Parts involved

pressure control solenoid ewiring harness

Related codes

P2719P2727P2729P2730P0965

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, gsi.ext.gm.com.