P07A5: Transmission friction element B stuck on
Transmission friction element B stuck on / clutch not releasing
Severity: Inspect soon
Kelley Blue Book rates this fairly serious and says not to keep driving with the code active, and PartsAvatar rates it moderate to high, because a clutch pack that will not release wears quickly.
P07A5 in short
P07A5 means the computer thinks one of the transmission clutch packs, called friction element B, is staying engaged when it should release. Low or dirty fluid is the first thing to check, then wiring and worn internals. Have it inspected soon and avoid long drives, because the wear can spread.
Automatic transmissions shift by applying and releasing clutch packs. The computer watches shaft speeds and expects each clutch to release on cue. P07A5 sets when friction element B looks like it is still applied.
The letter B is a label that depends on the transmission, so a service manual for your vehicle says which clutch it is. The code alone does not name the failed part.
Fluid and electrical problems are checked first because they are cheap to find. Uneven tire size or pressure can also confuse the speed comparison the computer makes, so tires are worth a look.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Low or dirty transmission fluid
Common general cause- Why it ranks here
- Both references list low or contaminated fluid first, since clutches release and apply by fluid pressure.
- What would change this
- Rises if the fluid is low, dark or smells burnt. Falls if fluid level and condition are normal.
Cause 2: Worn or damaged friction elements inside the transmission
Common general cause- Why it ranks here
- Both references list worn friction elements; KBB warns that ignoring the code leads to progressive wear.
- What would change this
- Rises with metal or clutch material in the fluid, slipping or flare. Falls if a fluid service and electrical checks clear the code.
Cause 3: Wiring, connector or water damage
Common general cause- Why it ranks here
- Both references list damaged wiring, loose connectors and water damage as causes.
- What would change this
- Rises if connectors show corrosion or the fault is intermittent. Falls if wiring and connectors are clean and dry.
Cause 4: Transmission or engine control module fault
Possible — needs testing- Why it ranks here
- Module failure is listed by both references but is a less common cause and is reached only after other causes are ruled out.
- What would change this
- Rises only after fluid, wiring and internal checks are clean and a shop confirms the module.
Cause 5: Mismatched tire size or pressure
Possible — needs testing- Why it ranks here
- KBB and PartsAvatar both say tire differences can upset the speed comparison the computer uses.
- What would change this
- Rises if tires differ in size or wear or one is low. Falls if tires match and are at the right pressure.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all stored codes and freeze-frame data with a scan tool, and note which other transmission codes are stored.
IfOther transmission or speed sensor codes are stored too
It meansWork on those first; they can set P07A5 as a side effect.
IfP07A5 is the only code
It meansCheck tires and fluid next.
Step 2: Check that all four tires match in size and are at the pressure on the door label.
IfTires are mismatched or one is low
It meansCorrect this, clear the code and see if it returns.
IfTires are fine
It meansCheck the fluid next.
Step 3: Check the transmission fluid level and condition by the method in the owner's manual. Many newer transmissions have no dipstick; leave those to a shop.
Warning:Run the check only as the owner's manual describes; the engine may need to be running and the transmission is hot, with moving parts nearby.
IfFluid is low, dark or smells burnt
It meansFluid is the likely issue; get it serviced.
IfFluid looks normal
It meansA shop should check wiring and the transmission internals.
Step 4: Have a shop inspect connectors and wiring, check live data for the clutch, and look for bulletins on your vehicle.
Warning:Transmission work involves hot fluid and heavy, moving parts; leave this to a shop.
IfWiring or connectors are damaged
It meansRepair the circuit.
IfThe fluid carries clutch material or the clutch does not release
It meansInternal wear is likely.
Points to: Worn or damaged friction elements inside the transmission
IfEverything checks out
It meansA control module fault is possible.
Symptoms
- Check engine light with unusual or erratic shift patterns
- Transmission slipping or reduced power Gets more serious: stop and have it checked.
- Fluid leaking from the transmission
How to fix
Step 1: Check that the tires match and are at the right pressure.
Step 2: Ask a dealer whether your VIN has a bulletin or software update for P07A5.
Parts and cost context
- Transmission control module (TCM):Replace only after fluid, wiring and internal checks. Labor varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
We don't have reviewed vehicle-specific evidence for P07A5 yet. The causes and tests above apply across vehicles.
Related codes
No curated relationships for P07A5 yet.
P07A5 questions
Can I keep driving with P07A5?
Kelley Blue Book says not to keep driving with the code active, because clutch wear builds. Short trips to a shop are more reasonable than commuting on it.
Sources and review
- P07A5 OBD-II Trouble Code: Transmission Friction Element B Stuck On
- OBD Code P07A5: Transmission Friction Element B Stuck On
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error