Transmission Checking/Fault-Tracing

Transmission checking/fault-tracing

Fault-tracing schedule

Contents

Fault-tracing consists of
- driving, see Driving
- fault-tracing, see Fault-tracing
- corrective action after test driving and fault-tracing, see Corrective action after test driving and fault-tracing.

Note! Read through the entire fault-tracing schedule before beginning work.

Driving
The operating temperature of the transmission fluid must be normal (85°C). See VIDA vehicle communication.
Start the car with gear selector in D position. Accelerate with an even throttle opening. A short judder should be felt in the car when shifting up between 2nd and 3rd gears.
Repeat this five to ten times until the symptom is noticeable.
Test with different throttle openings to ensure that the judder comes from the transmission and only occurs when shifting up between 2nd and 3rd. Shifting up from 2nd -3rd occurs between 40-140 km/h.
If the above conditions are met, continue with the fault-tracing as follows.

Fault-tracing
Faults which occur in the transmission but do not store any diagnostic trouble codes (DTC) can be mechanically fault traced by carrying out certain checks and adjustments.
Fault-trace in the following order.

Check the transmission fluid
Check the color. The color must be clear red or brown red. The color must not be pink. The oil must not be cloudy (Pink and / or cloudy oil means that coolant has entered into the transmission).

Check the expansion tank
Check that there is no transmission fluid in the radiator expansion tank (do not confuse it with black engine oil).

Corrective action
The following corrective action must be taken on finding any faults in the transmission fluid:
Replace the transmission assembly.
Replace the radiator including the extra cooler, if installed, and the hoses for the transmission.
Clean the expansion tank. Check and replace the expansion tank if necessary.

Corrective action after test driving and fault-tracing
The following work must be carried out if there are no faults with the oil and no other faults are found.
Replace the STH solenoid in the transmission. See Solenoid, line pressure, replacing Solenoid, Line Pressure, Replacing.
Fill the transmission with oil. Ensure that the oil level is correct. See Oil level, checking Checking Oil Level.
Test drive the car again. See Driving.

Note! Repeat the same shift five to ten times so that the transmission control module (TCM) adapts to the correct shift pressures.

If the problem persists: Replace the transmission assembly.