An automatic transmission works by manipulating the flow of pressurized hydraulic fluid (a.k.a. ATF), in order to move parts like clutch packs and gears. The pressure control solenoid is designed to allow the computer to control this pressurized transmission fluid. If the ECU detects a low voltage signal coming from pressure control solenoid F, a P2738 DTC will be stored.
What Transmission Do I Have?
How Serious is the Code?
A P2738 diagnostic trouble code is one of the more serious OBDII trouble codes, as it relates to the hydraulic pressure system that controls the transmission. If the pressure control solenoid is exhibiting signs of a short circuit, the gear changes will not occur in the way that they are programmed to. When this happens, some of the transmission problems that you may experience include delayed gear changes, slipping and engine stalling.
Symptoms
Symptoms of a P2738 include:
- Erratic shifting
- Delayed or harsh shifts
- Transmission slipping
- Engine stalls when coming to a stop
- Transmission gets stuck in a gear
- Vehicle won’t move when in gear
- Lower MPG
- Transmission overheats
- Limp mode
Causes
- Dirty transmission fluid / filter
- Not enough transmission fluid
- Damaged wiring/connectors
- Malfunctioning pressure control solenoid
- Defective transmission pump
- Blocked pressure passage
- Valve body issue
- TCM or ECU failure
How to Diagnose the Code?
To determine the cause of a P2738 DTC, you should first consider the level and condition of the transmission fluid. If your ATF is low or dirty, the pressure control solenoid will not be able to operate correctly, and that will trigger a P2738 diagnostic trouble code. The next thing that should be looked at is the wiring and connectors on the transmission wiring harness. If nothing is found up to this point, the pressure control solenoid, valve body, transmission pump and ECU/TCM should be tested.
What Transmission Do I Have?
What Repairs Will Fix P2738?
- Changing the fluid and filter
- Replace faulty pressure control solenoid
- Repair or replace a faulty transmission pump
- Repair or replace defective transmission valve body
- Transmission flush to clean passages
- Cleaning corrosion from connectors
- Repairing or replacing wiring
- Flashing or replacing PCM
Related Codes
- P2722 – Pressure Control Solenoid E
- P2723 – Pressure Control Solenoid E Perf or Stuck Off
- P2724 – Pressure Control Solenoid E Stuck On
- P2725 – Pressure Control Solenoid E Electrical
- P2726 – Pressure Control Solenoid E Intermittent
- P2727 – Pressure Control Solenoid E Ctrl Circ / Open
- P2729 – Pressure Control Solenoid E Ctrl Circ Low
- P2730 – Pressure Control Solenoid E Ctrl Circ High
