Transmission Friction Element "B" Apply Time Range/Performance

Possible causes

• CommonWorn clutch pack or band for element "B"
• CommonLow or degraded transmission fluid
• CommonLow line pressure - blocked filter, worn pump, failed pressure solenoid
• CommonSticking valve in the valve body
• PossibleInternal seal leak, so pressure bleeds away before the element grips
• PossibleAdaptation values learned around a developing fault and never reset

What you might notice

• Flaring between gears - engine speed rising during a shift
• Harsh or banging shifts
• Slipping under load
• Delayed engagement
• Burnt smell from the fluid

What to check, in order

1. Check the fluid level and condition first. It is the cheapest check and it explains more transmission complaints than every electrical fault combined. Look for clutch material in it - a dark grey gritty film means the elements are already wearing away.
2. Note whether shifts flare or bang. Flaring means the element is slipping as it applies; a bang means it is arriving too hard, and the two point in opposite directions.
3. A line pressure test separates worn elements from low pressure. Low pressure is repairable; worn elements usually mean a rebuild.
4. Read all codes - several friction element codes together usually mean fluid or pressure affecting the whole transmission rather than one worn clutch.
5. Check whether an adaptation reset is specified after repair.
6. Get a realistic assessment before spending. Several of these codes with burnt fluid rarely responds to anything short of a rebuild.