Transmission · Powertrain · generic (SAE-defined)
P0780: Shift Error
P0780 means the transmission computer commanded a gear change but did not see the expected change in gear ratio, indicating the shift did not complete correctly.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0780 sets
The powertrain or transmission control module (PCM/TCM) watches input and output shaft speeds during each commanded shift. If the gear ratio does not change as expected within the allowed time, or changes to the wrong ratio, it records P0780. This is a general shift-performance code, and the exact criteria are manufacturer-specific.
Common causes of P0780
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Low, burnt, or contaminated transmission fluid
- Faulty or sticking shift solenoid
- Sticking valves in the valve body
- Worn clutches or bands
- Faulty input or output speed sensor
- Wiring or connector problems in the solenoid circuits
- Outdated module software
P0780 symptoms
- Check engine light on
- Delayed, harsh, or missed shifts
- Engine speed flare during shifts
- Transmission stuck in one gear or limp mode
- Shudder or slipping under acceleration
How P0780 is diagnosed
- Check fluid level and condition first.
- Scan all codes; specific ratio or solenoid codes often point to the cause.
- Review freeze frame for which shift was in progress.
- Road test while monitoring commanded gear, actual ratio, and speed sensors.
- Test shift solenoids electrically and hydraulically.
- Perform line pressure testing and inspect the pan for debris.
- Check for software updates and technical service bulletins.
Typical fixes for P0780
- Service the fluid and filter
- Replace a faulty shift solenoid or solenoid pack
- Repair or replace the valve body
- Replace a faulty speed sensor
- Update PCM/TCM software if applicable
- Rebuild or replace the transmission if clutches are worn
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Manufacturer notes
Older definitions read 'Shift Malfunction'. Definitions can vary by manufacturer; check factory service information.
Related codes & warning lights
P0780 FAQ
What does code P0780 mean?
P0780 means the transmission computer commanded a gear change but did not see the expected change in gear ratio, indicating the shift did not complete correctly. The standard definition is "Shift Error."
Can I drive with a P0780 code?
Drive only to a repair shop if possible. A failed or slipping shift can leave the vehicle in the wrong gear or in limp mode, and continued slipping can quickly wear clutches.
Why is P0780 so vague?
It is a catch-all code meaning a shift did not happen correctly. Other codes stored with it and live data from a road test are what pinpoint the cause.
Can P0780 be caused by old fluid?
Yes. Degraded or low fluid can slow clutch apply and cause shift timing errors, so fluid condition is always one of the first checks.
Keep researching
More transmission codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.