P078B
Shift Timing Solenoid B Range/Performance
Shift timing solenoid B is electrically intact, but actual shift timing does not match the model — same failure modes as solenoid A (aged, dirty ATF), applied to the second timing channel.
Shift timing solenoid B is electrically intact, but actual shift timing does not match the model — same failure modes as solenoid A (aged, dirty ATF), applied to the second timing channel.
Common causes
- high
Aged solenoid with weakened force
One of the most commonly reported causes for this code — check this first.
Typical part cost: $440-2750
- low
Sensor element aged beyond calibration window
Less common, but worth ruling out after the more likely causes.
Typical part cost: $440-2750
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for P078B.
Unlock causesFree forever · No credit card
First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
Get the full step-by-step diagnosis
Create a free Wrenchify account to unlock the rest for P078B.
Unlock diagnosisFree forever · No credit card
Related codes
See related trouble codes
Create a free Wrenchify account to unlock the rest for P078B.
Unlock related codesFree forever · No credit card
Frequently asked questions
What does P078B mean?
P078B means "Shift Timing Solenoid B Range/Performance". It is a generic OBD-II code that points to a fault in the transmission.
What are the most common causes of P078B?
aged solenoid with weakened force; sensor element aged beyond calibration window; sensor mounting loose - signal damping — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Get the full P078B diagnosis for your vehicle
Year, make, model + step-by-step repair help — free plan included.