P2728 code meaning
Pressure Control Solenoid E Control Circuit Range/Performance
Powertrain system Generic code P27xx codes Check engine light
What P2728 means
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.
P2728 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2728
- MIL on Allison-equipped trucks
- History code without symptoms on GM six-speeds
- Firm shifts if pressure control is degraded
Common causes of P2728
- Most likelyCoil current deviating from command (resistance change, poor contact)
- PossibleFalse history code near 0 °C fluid temperature (GM 6T70/6T75)
- Less likelyUnstable supply voltage to the TCM
- Less likelyWorn solenoid E
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid eWiring harness
What each part of P2728 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7 | Area: transmission. |
| 28 | The exact fault in that area. |
What to do next
- Note P2728 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2728
What does P2728 mean?
P2728 means "Pressure Control Solenoid E Control Circuit Range/Performance". P2728 marks the circuit of solenoid E as working but not plausible. It is a generic code, so it means the same on every make.
Is it safe to drive with P2728?
Drive gently and only to a workshop. With P2728 the car can go into limp mode (reduced power) to protect itself.
Will P2728 fail an emissions test?
Yes, it can. P2728 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2728 to fix?
Difficulty: medium. A typical repair takes 0.3 to 5 hours of work. This is a job for a workshop.
Will P2728 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.