What it means
The transmission control module detected that friction element B did not release as expected. The code alone does not identify the cause.
At a glance
- Usually lights the check-engine light
How it works
The transmission control module monitors whether friction element B releases when it is no longer needed for the selected gear. P07A5 means the module detects that element B remains applied, which may interfere with subsequent shifts; the code does not by itself pinpoint a stuck piston, debris, wear, or control fault.
Common causes
Most likely first.
- Stuck apply piston
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Review freeze-frame and live data for the commanded gear and shaft speeds to identify when element B should have released but did not.
- Check fluid level and condition using the vehicle maker’s procedure, looking for degraded fluid or contamination that can contribute to sticking.
- Inspect transmission wiring and connectors for damage or poor contact that might hold element B’s control solenoid in the wrong state.
- On a controlled road test, check whether harsh or abnormal shifts occur specifically when the gear change requires element B to release.
- If fluid and wiring checks are sound, test solenoid and valve-body operation and hydraulic release control against the manufacturer's specification.
- If hydraulic control releases properly but element B stays applied, inspect its piston and friction parts for sticking, debris, or wear.
Common fixes
- Correct the fluid level or replace contaminated or degraded fluid with the specified type.
- Repair wiring or connector faults affecting element B control.
- Repair or replace a sticking solenoid or valve-body component.
- Clean or repair a sticking apply piston and replace damaged or worn element B components.
Can I keep driving?
Avoid driving if shifts are binding or harsh, because element B remaining applied can overheat the transmission and damage other friction parts. If the vehicle cannot shift normally or enters limp mode, stop safely and arrange recovery.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.