Excessive shock or flares on 1-2 upshift or 2-1 downshift
Check for a stored DTC, and check for loose connections.
Test the solenoid valve function with the HDS.
Inspect the A/T clutch pressure control solenoid valve body gasket, ATF feed pipes, and O-rings for wear and damage.
Inspect the O-rings, and check the shift solenoid valve for seizure.
Check for clogged orifice in the transmission fluid pressure switch connector. If the orifice is clogged, remove it and clean the connector.
Check for clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
Check the 1st and 2nd clutch pressures.
Inspect the 1st accumulator piston, O-ring, and spring for wear and damage in the servo body.
Inspect the 2nd accumulator piston, O-ring, and spring for wear and damage in the servo body.
Check the 1st check ball and 2nd check ball for stick in the main valve body.
Inspect the secondary shaft, 1st clutch, and 2nd clutch for wear and damage.
Inspect the clutch piston, clutch piston check valve, and O-rings. Check the spring retainer for wear and damage. Inspect the clearance between the clutch end-plate and the top disc. If the clearance is out of tolerance, inspect the clutch discs and plates for wear and damage, and inspect the clutch wave-plate height. If the discs and plates are worn or damaged, replace them as a set. If the wave-plate height is out of tolerance, replace the wave-plate. If they are OK, adjust the clearance with the clutch end-plate.
Inspect the 2nd clutch feed pipe. If the 2nd clutch feed pipe is scored, replace the end cover.
Replace the secondary shaft if the bushing for the 2nd clutch feed pipe is loose or damaged.
Check the lock-up shift valve in the regulator valve body for free movement, and check the valve spring for wear and damage.
Shift solenoid valve D defective
A/T clutch pressure control solenoid valve A defective
A/T clutch pressure control solenoid valve B defective
A/T clutch pressure control solenoid valve C defective
2nd clutch transmission fluid pressure switch defective
Foreign material in separator plate orifice
1st accumulator defective
2nd accumulator defective
1st check ball stuck
2nd check ball stuck
Lock-up shift valve defective
1st clutch defective
2nd clutch defective