OBD2 Car ScannerWhat does P078D mean?
P078D stands for Shift Timing Solenoid B High. The transmission control system has found a problem. You may notice harsh, late or missing gear changes.
Powertrain codes cover the engine, transmission and emissions. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Low or old transmission fluid
- Faulty shift solenoid
- Faulty transmission speed or temperature sensor
- Damaged wiring
- Internal transmission wear
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does P078D mean?
P078D means “Shift Timing Solenoid B High”. It belongs to the transmission group: The transmission control system has found a problem. You may notice harsh, late or missing gear changes.
Is it safe to drive with P078D?
Avoid driving long distances. This kind of fault can cause damage or affect safety, so get it checked as soon as possible.
How do I clear P078D?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- P0789Shift Timing Solenoid A Intermittent
- P078AShift Timing Solenoid B Malfunction
- P078BShift Timing Solenoid B Range/Performance
- P078CShift Timing Solenoid B Low
- P078EShift Timing Solenoid B Intermittent
- P0790Normal/Performance Switch Circuit Malfunction
- P0791Intermediate Shaft Speed Sensor A Circuit
- P0792Intermediate Shaft Speed Sensor A Circuit Range/Performance
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.