Road Test
Road Test^ Perform the road test using a scan tool.
^ This test should be performed when traffic and road conditions permit.
^ Observe all traffic regulations.
The TCM calculates upshift points based primarily on 2 inputs: throttle angle and vehicle speed.
When the TCM wants a shift to occur, an electrical signal is sent to the shift solenoids which in turn moves the valves to perform the upshift.
The shift speed charts reference throttle angle instead of "min. throttle" or "wot" to make shift speed measurement more uniform and accurate. A scan tool should be used to monitor throttle angle. Some scan tools have been programmed to record shift point information. Check the introduction manual to see if this test is available.
Upshift Procedure
With gear selector in drive (D)
1) Look at the shift speed chart contained in this section and choose a percent throttle angle of 10 or 25%.
2) Set up the scan tool to monitor throttle angle and vehicle speed.
3) Accelerate to the chosen throttle angle and hold the throttle steady.
4) As the transaxle upshifts, note the shift speed and commanded gear changes for:
^ 2nd gear.
^ 3rd gear.
^ 4th gear.
CAUTION: Shift speeds may vary due to slight hydraulic delays responding to electronic controls. A change from the original equipment tire size affects shift speeds.
Note when TCC applies. This should occur in fourth gear. If the apply is not noticed by an RPM drop, refer to the Torque Converter Lock-up Clutch Diagnosis information contained in this section.
The Lock-up clutch should not apply unless the transaxle has reached a minimum operating temperature of 8° C (46° F) Trans Temp and engine coolant temp of 50° C (122° F).
5) Repeat steps 1 - 4 using several different throttle angles.
Part Throttle Detent Downshift
At vehicle speeds of 55 - 65 km/h (34 - 40 mph) in 4th gear, quickly increase throttle angle to greater than 50%.
Verify that:
^ TCC apply.
^ Transaxle downshift to 3rd gear.
^ Solenoid 1 turns ON to OFF.
^ Solenoid 2 turns OFF.
Full Throttle Detent Downshift
At vehicle speeds of 55 - 65 km/h (34 - 40 mph) in 4th gear, quickly increase throttle angle to its maximum position (100%).
Verify that:
^ TCC release.
^ Transaxle downshift to 2nd gear immediately.
^ Solenoid 1 turns ON to OFF.
^ Solenoid 2 turns OFF.
Manual Downshifts
1) At vehicle speeds of 60 km/h (40 mph) in 4th gear, release accelerator pedal while moving gear selector to Manual 3rd. Observe that:
^ Transaxle downshift to 3rd gear immediately.
^ Engine slows vehicle down.
2) Move gear selector back to overdrive (D) and accelerate to 50 km/h (31 mph). Release the accelerator pedal and move the gear selector to Manual 1st and observe that:
^ Transaxle downshift to 2nd gear immediately.
^ Engine slows vehicle down.
CAUTION: A Manual 1st - 3rd Gear Ratio will occur at high speeds as an upshift safety feature. Do not attempt to perform this shift.
Coasting Downshifts
1) With the gear selector in Overdrive (D), accelerate to 4th gear with TCC applied.
2) Release the accelerator pedal and lightly apply the brakes, and observe that:
^ TCC release.
^ Down shifts occur at speeds shown ON the shift speed chart.
Manual Gear Range Selection
Upshifts in the manual gear ranges are controlled by the shift solenoids. Perform the following tests by accelerating at 25% TP sensor increments.
Manual 3rd
^ With vehicle stopped, move the gear selector to Manual 3rd and accelerate to observe:
- 1 - 2 shift.
- 2 - 3 shift.
Manual 2nd
^ With vehicle stopped, move the gear selector to Manual 2nd and accelerate to observe:
- 1 - 2 shift.
^ Accelerate to 40 km/h (25 mph) and observe:
- 2 - 3 shift does not occur.
- TCC does not apply.
Manual 1st
^ With vehicle stopped, move gear selector to Manual 1st. Accelerate to 30 km/h (19 mph) and observe:
- No upshifts occur.
Reverse (R)
^ With vehicle stopped, move gear selector to R (Reverse) and observe:
- Solenoid 1 is OFF.
- Solenoid 2 is OFF.
Use a scan tool to see if any transaxle trouble codes have been set. Refer to and repair the vehicle as directed. After repairing the vehicle, perform the hoist test and verify that the code has not set again.
If the transaxle is not performing well and no trouble codes have been set, there may be an intermittent condition. Check all electrical connections for damage or a loose fit. You also have to perform a snapshot test which can help catch an intermittent condition that dose not occur long enough to set a code.
You may want to read Electronic Component Diagnosis in this section to become familiar with transaxle conditions caused by transaxle electrical malfunction.
If no trouble codes have been set and the condition is suspected to be hydraulic, take the vehicle on a road test.