P0829
5-6 Shift
Transmission
Generic OBD-II
Medium
What it means
P0829 sets when the transmission control module detects a problem completing the shift between 5th and 6th gears. The engine still starts and the car drives, but the upper-gear shift may be slow, harsh, or incomplete. It usually points to low or dirty fluid, a 5-6 shift solenoid or valve-body fault, or internal wear.
Medium
Can I keep driving? Usually drivable, but the transmission may shift harshly or refuse to reach top gear — raising rpm and fuel use at highway speed until fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Delayed or harsh shift between 5th and 6th gears
- Slipping or hunting between the upper gears
- Transmission won't reach top gear (higher rpm on the highway)
- Reduced fuel economy at cruising speed
Common causes
Most likely first
- Low or contaminated transmission fluidLikely
- Faulty 5-6 shift solenoid or a sticking valve bodyCommon
- Worn clutches, bands, or gear components for the upper gearsCommon
- Faulty transmission control module (TCM)Less often
How to diagnose & fix
Work through it in order
- Check transmission fluid level and condition first; top up or service if low or burnt.
- Scan for companion transmission codes and read freeze-frame data to see when the shift fails.
- Test the 5-6 shift solenoid and inspect the valve body for sticking or debris.
- If shifting still slips, inspect internal clutches and gears for wear.
- Replace the TCM only after wiring, fluid, and mechanical causes are ruled out. Clear and road-test.
FAQ
Quick answers
Is it safe to drive with P0829?+
Short trips are usually fine, but repeated slipping or harsh shifts in the upper gears can wear the transmission. Get it checked soon.
Can I just clear P0829?+
It will come back on the next drive that reaches those gears unless the underlying fluid, solenoid, or mechanical fault is fixed.
Related codes
Often seen with P0829
Read & clear P0829 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