P0780 Code: Shift Malfunction
A gear change didn't complete the way the TCM expected, but it can't pin the fault to one part.
At a glance
Severity: Moderate
- Meaning
- Shift Malfunction
- System
- Transmission · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $100–$5,500
- DIY difficulty
- Hard
P0780 is a broad code: during or after a shift, the TCM compared input and output shaft speeds and found that the expected ratio wasn't reached in time, or that the shift slipped or flared beyond its limits. Unlike P0781 (1-2) or a solenoid code, it doesn't name a specific gear change or component, so it is a starting point rather than a diagnosis. Honda automatics log it often, where it tends to trace back to a shift solenoid, a clutch pressure control solenoid or worn fluid; on other makes worn clutch packs and valve body problems are just as likely. The key to fixing it is working out which shift is misbehaving.
Can I keep driving? Usually drivable with care if shifts are only a little rough. If the engine flares between gears, the transmission slips or it goes into limp mode, keep trips short and slow – slipping clutches wear quickly and contaminate the fluid.
How to read P0780
- P Powertrain
- 0 Generic (SAE)
- 7 Transmission
- 80 Specific fault
Symptoms
- Engine rpm flare between gears
- Delayed, soft or erratic upshifts
- Occasional harsh bang on one shift
- Transmission slipping under acceleration
- Limp mode after the fault is detected, back to normal after a restart
- Check engine light with a D indicator flashing on some Honda models
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Low, worn or wrong-type transmission fluid
- Shift or pressure control solenoid sticking
- Worn clutch packs or bands
- Valve body wear or sticking shift valve
- Input or output speed sensor giving a bad signal
- TCM software or learned shift values out of range
Diagnosis step by step
Look for companion codes
Read all TCM codes. A gear-ratio code (P0731–P0735), a 1-2 shift code like P0781 or a solenoid code stored with P0780 tells you where to focus; P0780 alone means you'll need to find the faulty shift yourself.
Tools: OBD-II scanner
Check the fluid first
Check level and condition by the factory method and confirm the correct fluid type is in it. Many shift complaints on Honda and other Japanese automatics clear up once the correct fluid is at the proper level.
Tools: Flashlight, Towels & shallow pan
Log each upshift
Record engine rpm, input and output speed and commanded gear through all shifts at light and moderate throttle. The shift with a long ratio change, an rpm flare or a bang is the one to chase.
Tools: OBD-II scanner
Test the solenoids for that shift
Using the service information, identify the shift and pressure solenoids involved in the faulty shift and check their resistance and operation. On transmissions with external solenoids, their screens should be inspected too.
Tools: Multimeter, OBD-II scanner
Inspect the pan and filter
Friction material or metal in the pan points to a worn clutch pack rather than a solenoid. A little fine debris is normal; flakes and heavy sludge are not.
Tools: Towels & shallow pan, Torque wrench
Update software and relearn
Many manufacturers have released TCM updates that change shift control. After any fix, reset or relearn the shift adaptations and road test until shifts are consistent.
Tools: OBD-II scanner
Where the parts are
- 1Battery
- 2Alternator
- 3Engine computer (ECM)
- 4CAN bus
- 5Transmission
- 6Wheel speed sensor
- 7High-voltage battery
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Fluid drain-and-fill with correct fluid | No | $120–$350 |
| Replace a shift or pressure control solenoid | No | $200–$650 |
| TCM software update and relearn | No | $100–$250 |
| Valve body repair or replacement | No | $700–$1,600 |
| Transmission rebuild or replacement | No | $2,800–$5,500 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Honda
P0780 is common on Honda Accord, Odyssey, CR-V and Pilot automatics. Honda's usual approach is to check fluid level and condition, refill with genuine Honda ATF, and test the shift and clutch pressure control solenoids, which mount on the outside of the case, before looking at internal parts.
Field data
| Mazda | 3 | Mazda6, Mazda3 | |
|---|---|---|---|
| Honda | 2 | Accord Crosstour, Cr-V | |
| Nissan | 2 | Maxima, Titan |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P0780 turns on the check engine light, which is an automatic fail at an OBD smog or emissions test. Repair it and let the monitors complete before retesting.
Frequently asked questions
Why doesn't P0780 say which gear is the problem?
Because the TCM saw a shift-quality problem it couldn't assign to a specific shift or component. Logging each shift with a scan tool fills in what the code doesn't tell you.
Will changing the transmission fluid fix P0780?
If the fluid is low, old or the wrong type, a drain-and-fill with the right fluid often helps, especially on Hondas. If friction material is present or slipping continues, internal repair is likely.
Is P0780 the same as a slipping transmission?
It can be caused by slipping, but also by a slow shift or a stuck solenoid without any clutch wear. The data log shows which case you have.
Why is the D light flashing on my Honda?
On many Hondas a flashing D indicator means the transmission computer has stored a fault. It's a hint to have the transmission codes read, not a separate problem.