What it means
Voltage on the pressure control solenoid D control line is below the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
Pressure control solenoid D is an electrically controlled valve that helps regulate hydraulic pressure for transmission operation. P2720 sets when the control circuit voltage is below the expected range, which can result from a short to ground, a faulty coil, or a poor connection.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in solenoid coil
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine or transmission warning light on
- Harsh or delayed shifts
- Transmission may enter limp mode
- Slipping or reduced drive
How to diagnose it
- Record freeze-frame data and scan for related transmission codes to see whether the low-circuit fault appeared with a particular gear or operating condition.
- Inspect the solenoid D connector and harness for chafing, fluid or water intrusion, corrosion, and loose or pushed-back terminals.
- Watch the solenoid D circuit data while gently moving the harness to check for an intermittent drop in the reported signal.
- Using the wiring diagram, test the control wire for a short to ground and check connector continuity through the transmission harness.
- Measure solenoid D coil condition and controller output against the manufacturer's specification to distinguish a coil fault from a wiring or driver fault.
Common fixes
- Clean and secure the solenoid D connector; repair corroded or loose terminals.
- Repair the control wire where it is shorted to ground or damaged.
- Replace pressure control solenoid D if its coil fails testing.
- Repair the transmission controller circuit only after wiring and solenoid tests isolate the controller as the cause.
Can I keep driving?
Avoid towing or hard acceleration if shifts are harsh, slipping, or reduced, and limit driving if the transmission enters limp mode. Incorrect pressure control can worsen slipping and transmission heat.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.