P2738 reports a control line on solenoid F that reads too low, which in practice means a short to ground. In GM's 2025 table 25OBDG03A an impedance below 0.5 Ohm between the signal and controller ground, lasting 0.3 s inside a 0.5 s sampling period, is a Type A fault in one trip; the valve there controls a clutch on the nine- or ten-speed, line pressure on the eight-speed or the CVT binary pump. The eight-speed table of 2016 uses the same timing. The Corvette dual-clutch TCM tests the clutch cooling valve with its driver switched on and sets P2738 when the measured pin voltage remains below roughly 1.7 V for 150 ms. Ford's TR9070 labels the same condition shorted switch on the odd clutch cooling valve. A grounded line can energise the valve permanently.
Medium severity. Can I keep driving?Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
Symptoms
- MIL on and fail-safe gear
- Harsh engagements or clutch drag
Most likely causes
- Control wire chafed through to ground
- Shorted turns in solenoid F
- Fluid or metal debris bridging connector pins
- Faulty TCM output stage
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P2738 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 7: Transmission
- 38: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2738?
Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
What causes code P2738?
The most common causes are: control wire chafed through to ground; shorted turns in solenoid F; fluid or metal debris bridging connector pins.
Related codes
- P2734Pressure Control Solenoid F Electrical
- P2736Pressure Control Solenoid F Control Circuit/Open
- P2737Pressure Control Solenoid F Control Circuit Range/Performance
- P2739Pressure Control Solenoid F Control Circuit High
- P2729Pressure Control Solenoid E Control Circuit Low
- P2814Pressure Control Solenoid G Control Circuit Low
Sources
- gsi.ext.gm.com: 25OBDG03A
- gsi.ext.gm.com: 16OBDG03 Transmission Diagnostics
- gsi.ext.gm.com: 23OBDG07
- fordservicecontent.com: OBDSM2400OUTPUT 16Jul2024 WSM final V2 MCS7001
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.