Pressure Control Solenoid C Intermittent
What it means
P0799 means the transmission control module detected an intermittent fault in the pressure control solenoid C circuit, which regulates hydraulic line pressure. When the signal drops out, line pressure wavers, so the transmission occasionally slips or shifts harshly rather than failing outright. It won't cause a no-start; the goal is to find the intermittent wiring or solenoid fault before it becomes constant and wears the clutches.
Can I keep driving? Shifts may occasionally slip or turn harsh as pressure control drops out; drivable for now, but fix it before it becomes constant.
Common symptoms
What you'll notice
- Intermittent slipping or improper shifts
- Harsh or delayed shifting
- Reduced fuel economy
- Check-engine light on (may come and go)
Common causes
Most likely first
- Intermittent wiring or connector fault in the pressure control solenoid C circuitLikely
- Faulty pressure control solenoid CCommon
- Low or contaminated transmission fluidCommon
- Transmission control module (TCM) faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to capture the conditions when it set.
- Wiggle-test the solenoid C wiring and connector to reproduce the fault.
- Check transmission fluid level and condition.
- Test the pressure control solenoid C resistance and operation.
- If wiring and solenoid are good, suspect the TCM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0799?+
Can I just clear P0799?+
Related codes
Often seen with P0799
Read & clear P0799 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.