Additional ATF Checks on Vehicles With a Secondary ATF Cooler

Additional ATF Checks on Vehicles With a Secondary ATF Cooler

These checks must be carried out whenever the secondary ATF cooler is drained or replaced.

Checking preconditions
- All electrical consumers and the air conditioning system must be switched off
- ATF topped up
- Vehicle level
- Selector lever in "P", engine idling

Connecting VAS 5051 vehicle diagnostic, testing and information system
All functions, which could previously be performed with VAG 1551 can also be performed with the new tester VAS 5051 in the operating mode "Vehicle self-diagnosis":




- With ignition switched off, connect tester VAS 5051 to diagnostic connection using diagnosis cable 5051/1 or 5051/3.




- Switch on tester-arrow-.
Now the tester requires approx. 3 minutes to run up.

Read ATF temperature
- Switch on ignition.
- Select mode of operation: press button on touch screen for "Vehicle self-diagnosis".
- Select vehicle system: select "02. transmission electronics" on touch screen.
- Check and confirm that the control module number of the system selected.
- Select diagnostic function: at this point, all diagnostic functions are available.
- Select "08. read measured value blocks" on the touch screen.
- Select display group 4 via "Measured value block" and "Change display group number".
The upper display zone shows the ATF temperature.

- Start engine.
- Let engine run until ATF temperature reaches at least 85°C. It might be necessary to take vehicle out for a short drive to reach this temperature.

The thermostat at the inlet of the secondary ATF cooler does not open until the temperature reaches 80°C. ATF can then flow into the cooler.




- Bring ATF to test temperature.
Test temperature: 85°C

- Turn engine off and let ATF cool down until temperature is below 35°C.
- Check ATF level and top up, ATF Level, Checking and Topping Up