P099D
Shift Solenoid H Control Circuit Range/Performance
Transmission
Generic OBD-II
Medium
What it means
P099D means the transmission control module sees shift solenoid H performing outside its expected range — the solenoid that helps engage a gear is responding incorrectly. It can stem from a failing solenoid, a poor electrical connection, or low/contaminated fluid, and it typically shows up as rough or erratic shifting.
Medium
Can I keep driving? Usually driveable but with rough or erratic shifting; the transmission may enter limp mode — repair before slipping causes wear.
Common symptoms
What you'll notice
- Check-engine light on
- Very rough or harsh gear shifts
- Erratic or delayed shifting
- Transmission in limp/failsafe mode
Common causes
Most likely first
- Failed shift solenoid HLikely
- Poor electrical connection or wiring fault in the solenoid circuitCommon
- Low transmission fluid levelCommon
- Dirty or contaminated transmission fluidLess often
- Faulty valve body assemblyLess often
How to diagnose & fix
Work through it in order
- Check the transmission fluid level and condition; top up or service if low, burnt, or contaminated.
- Inspect the shift solenoid H wiring and connector for corrosion, chafing, or a loose fit.
- Test the solenoid's resistance and response; replace shift solenoid H if it is out of range or sticking.
- If the fluid shows heavy debris or the solenoid tests good, inspect the valve body for wear.
FAQ
Quick answers
Is it safe to drive with P099D?+
Short-term yes, but very rough shifts and possible slipping can damage the transmission. Check the fluid and repair the cause promptly.
Can I just clear P099D?+
It will come back until the solenoid, wiring, or fluid issue is corrected — clearing does not address the underlying fault.
Related codes
Often seen with P099D
Read & clear P099D yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX