Fluid - A/T: Testing and Inspection
Line pressure/stall speed, checkSpecial tools: 999 2531,999 5074
Note: As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information is always correct.
Checking the oil level
Check the oil level. See Oil level, checking.
Ignition off.
Removing the air cleaner (ACL) housing
Only applies to vehicles with B5254T4 engines
Remove the cover at the side of the air cleaner (ACL) housing.
Unhook the holder with the transmission connectors from the bracket. Remove the bracket from the side member.
Remove the air cleaner housing ACL assembly with the intake pipe. Pull the air cleaner (ACL) housing out of its mountings.
Connecting the manometer
Remove the test plug from the transmission. Install nipple 999 5074.
Connect the hose and manometer 999 2531 to the nipple.
Does not apply to vehicles with B5254T4 engines
Installing the air cleaner (ACL) housing
Install the air cleaner (ACL) housing, including all hoses and electrical terminals.
Checking the engine idling speed
Start the engine. Allow it to idle in neutral.
Check the engine idle speed. See the table below.
Checking the line pressure
Depress the brake pedal.
Move the gear selector into its various positions. Read off the line pressures.
Checking the stall speed
Check the stall speed when checking the line pressure.
The stall speed test gives an indication of the condition of the torque converter, the transmission clutches and the engine.
For the test to be accurate the following conditions must be met:
^ the engine must be properly tuned
^ the line pressure must be correct
^ the oil level in the transmission must be correct and the transmission must be at operating temperature.
Note: Never conduct a stall speed check when the line pressure is too low.
Check
The air conditioning (A/C) must be turned off. Block all four wheels.
Start the engine.
Caution: Apply the parking brake. Press down hard on the brake pedal using your left foot during the test.
Move the gear selector to position D. Fully depress the accelerator pedal (AP) for a maximum of 5 seconds. Read off the maximum engine speed (RPM) and the line pressure. Compare to the table below.
Note: Do not test the stall speed for longer than 5 seconds.
Repeat the test with gear selector in position R.
Compare to the table.
If the engine speed (rpm) exceeds the value in the table, see High stalling speed. If the engine speed (rpm) is less than the value in the table, see Low stalling speed.
High stalling speed
The test conditions described in Check above, have been met. Is the acceleration time from 0-100 km/h normal?
If the stalling speed recorded exceeds the normal value by more than 300 rpm:
Check if the oil is discolored or smells burnt. See Oil grade, checking.
If the oil is OK, replace the torque converter. (See the procedures that also apply when replacing the torque converter)
Dirty oil indicates worn or burnt clutch plates. Replace the transmission.
Check the stalling speed again after replacing the transmission.
Low stalling speed
The test conditions described in Check above have been met.
Try a new torque converter if the stall speed recorded is below the normal value by more than 300 rpm.
Check the stalling speed again after replacing the torque converter
Replace the transmission if the fault persists.
Noise:
Replace the transmission:
Check the stalling speed again after replacing the transmission.
After the check is completed:
Ignition off.
Remove the air cleaner housing (ACL) assembly with the intake pipe.
Remove both the manometer connection and the manometer.
Install:
^ the test plug. Check that the O-ring is undamaged. Replace if necessary. Tighten. See Tightening torque
^ the air cleaner (ACL) housing with all hoses and electrical terminals.
Only applies to vehicles with B5254T4 engines
After the check is completed:
Ignition off.
Remove both the manometer connection and the manometer.
Install:
^ the test plug. Check that the O-ring is undamaged. Replace if necessary. Tighten. See Tightening torque
^ the bracket for the side member
^ the holder for the connectors on the bracket
^ the cover for the bracket.
Test Drive Form, description
This schedule is intended to provide guidelines when test driving a car to evaluate complaints about the AW 55-50 and AW50AWD automatic transmissions.
Please observe speed limits.
Before the test drive:
- Check the oil level in the transmission before test driving. See Oil level, checking
- Check that the gear selector cannot be moved with the ignition off
- Check that the gear selector cannot be moved with the ignition on and the brake pedal unaffected.
Test driving:
Check the operation of the park / neutral position (PNP) switch:
It should only be possible to start the engine when the gear selector is in the Neutral or Park positions.
Try to start the engine with the gear selector in any other position than P or N.
Check the gear selector positions:
Check that the selector engages in each position, and that it does not try to " jump" out of the selected position.
Check the back-up gear:
Back up the car in the normal way. Check that the back-up light comes on.
Listen for mechanical noises:
Start the car with the gear selector in position D. Drive the car so that the transmission shifts up and down. Listen for abnormal noises from the transmission. If you hear noises, stop the test drive and return to the workshop. Fault-trace the relevant symptoms in the symptom manager.
Check the function of the transmission while driving
Economy mode, Sport mode
During normal driving the transmission uses the economy mode. The transmission shifts smoothly. In the event of rapid acceleration, the transmission switches to the sport mode. Shifting in sport mode is quicker, although still smooth. Check that the transmission is working correctly.
Start the car with the gear selector in position D. Note whether the gears slip or shifting is harsh. Check that the lock-up function engages.
Keep the car stationary on a flat road with the gear selector in N position. Release the brake and accelerate a little. Does the car move forward? Start in position D. Drive the car at approximately 70 km/h so that 5th gear engages. Shift the gear selector to positions 4, 3 and L.
Check that there is engine braking.
Stop the car on a slope. Shift the gear selector to position P.
Release the brake. Does the car move?
Winter (W)
Start the car with the gear selector in position D. The transmission should start in third gear and give a smooth take-up from standstill. Check that the kickdown function operates.