Automatic Transmission

Symptom Troubleshooting Index (cont'd)

 14-9  
Symptom Probable cause(s) Notes
Harsh upshift:

2nd to 3rd gear
  1. 3rd clutch defective
  2. A/T clutch pressure control solenoid valve A defective
  3. A/T clutch pressure control solenoid valve B defective
  4. CPC valve defective
  5. 2nd accumulator defective
  6. 2nd orifice control valve defective
  7. Foreign material in main orifice
  8. Torque converter clutch solenoid valve defective
  9. Mainshaft speed sensor defective
  10. Countershaft speed sensor defective
  • Inspect the clutch piston, clutch piston check valve and O-rings. Check the spring retainer for wear and damage. Inspect the clutch end plate-to-top disc clearance. If the clearance is out of tolerance, inspect the clutch discs and plates for wear and damage. If the discs and plates are worn or damaged, replace them as a set. If they are OK, adjust the clearance with the clutch end plate.
  • Check the 2nd and 3rd clutch pressures.
  • Check the indicator light indication and check for loose connectors. Inspect the A/T clutch pressure control solenoid valve filter/gasket for wear and damage. If the A/T clutch pressure control solenoid valve is stuck, inspect the CPC valve.
  • Inspect the O-rings and check the torque converter clutch solenoid valve for seizure.
  • Check the mainshaft speed sensor installation.
  • Check the countershaft speed sensor installation.
  • If the ATF strainer is clogged with particles of steel or aluminium, inspect the ATF pump. If the ATF pump is OK and no cause for the contamination is found, replace the torque converter.
Harsh upshift:

3rd to 4th gear
  1. 4th clutch defective
  2. A/T clutch pressure control solenoid valve A defective
  3. A/T clutch pressure control solenoid valve B defective
  4. CPC valve defective
  5. 3rd accumulator defective
  6. 3-4 orifice control valve defective
  7. Foreign material in main orifice
  8. Torque converter clutch solenoid valve defective
  9. Mainshaft speed sensor defective
  10. Countershaft speed sensor defective
  • Inspect the clutch piston, clutch piston check valve and O-rings. Check the spring retainer for wear and damage. Inspect the clutch end plate-to-top disc clearance. If the clearance is out of tolerance, inspect the clutch discs and plates for wear and damage. If the discs and plates are worn or damaged, replace them as a set. If they are OK, adjust the clearance with the clutch end plate.
  • Check the 3rd and 4th clutch pressures.
  • Check the indicator light indication and check for loose connectors. Inspect the A/T clutch pressure control solenoid valve filter/gasket for wear and damage. If the A/T clutch pressure control solenoid valve is stuck, inspect the CPC valve.
  • Inspect the O-rings and check the torque converter clutch solenoid valve for seizure.
  • Check the mainshaft speed sensor installation.
  • Check the countershaft speed sensor installation.
  • If the ATF strainer is clogged with particles of steel or aluminium, inspect the ATF pump. If the ATF pump is OK and no cause for the contamination is found, replace the torque converter.