What it means
A general fault in pressure control solenoid H. Detected via electrical resistance, response to commanded duty cycle, or downstream pressure measurement.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Pressure control solenoid H changes hydraulic pressure in its assigned transmission circuit in response to commands from the transmission control module. P2816 indicates a general fault with H, which may be detected as abnormal coil resistance, a mismatch between commanded and observed operation, or an unexpected pressure response.
Common causes
Most likely first.
- Aged solenoid coil resistance drift
- Worn valve body bore around the solenoid
Symptoms
- Check-engine or transmission warning light
- Harsh or delayed shifts
- Transmission may slip or hesitate
- Transmission may enter limp mode
How to diagnose it
- Read freeze-frame data and all transmission codes to identify the conditions when the H fault appeared and whether other pressure-control codes are present.
- Check transmission fluid level and condition using the vehicle's specified procedure, since fluid problems can affect pressure response.
- Inspect solenoid H's connector and harness for loose, corroded, or damaged terminals and wiring.
- Measure solenoid H coil resistance with the circuit isolated as specified, and compare it with the manufacturer's specification.
- Use scan-tool data to compare the command to solenoid H with available pressure or shift response data.
- If electrical checks pass but H's pressure response remains abnormal, inspect the valve body and solenoid bore for wear or sticking.
Common fixes
- Repair a loose, corroded, or damaged solenoid H connector or wire.
- Replace solenoid H if its coil resistance is outside the manufacturer's specification.
- Service the valve body if the H solenoid bore is worn or binding.
- Correct a fluid level or condition problem using the specified service procedure.
Can I keep driving?
Limit driving, especially under load, because slipping or delayed shifts can overheat and damage the transmission. If shifts become unpredictable or limp mode engages, stop in a safe place and arrange diagnosis.
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.