P27DB: Pressure Control Solenoid T Electrical

What it means

The transmission control module detects an electrical fault associated with pressure control solenoid T.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Pressure control solenoid T is an electrically operated valve used by the transmission control module to regulate hydraulic pressure. P27DB sets when the module detects an electrical fault associated with solenoid T, such as a failed coil, an open or shorted wire, or poor connector contact.

Common causes

Most likely first.

1. Faulty solenoid coil
2. Open or short in solenoid wiring
3. Poor connector contact

Symptoms

• Transmission warning light may illuminate
• Harsh or delayed shifting
• Transmission may enter limp mode

How to diagnose it

1. Record freeze-frame data and all transmission codes with a scan tool before clearing P27DB.
2. Inspect the solenoid T connector and harness for loose contacts, corrosion, chafing, or broken wires.
3. Check the solenoid T coil and compare its resistance with the manufacturer's specification.
4. Test the solenoid T circuit for opens or shorts using the manufacturer's procedure.
5. If the coil and wiring pass, check connector contact and the TCM output circuit as specified by the manufacturer.

Common fixes

• Secure or repair a poor solenoid T connector contact.
• Repair open, shorted, or damaged wiring in the solenoid T circuit.
• Replace pressure control solenoid T if its coil fails the manufacturer's test.
• Repair the TCM control circuit if testing locates the electrical fault there.

Can I keep driving?

Avoid towing and hard acceleration because the transmission may shift harshly or enter limp mode. Stop if it slips or loses drive, since continued driving can lead to further damage.