SSANGYONG 1999 Musso Service Manual page 738

OM600 ENGINE CONTROLS 1F3-9
Test step 2
Connect vacuum pump (14) with Y adapter to PLA
vacuum unit (5). Run the engine at idle speed.
Vacuum drops to '0' at approx. 30°C of the thermovalve.
NO
YES
Faulty thermovalve.
Defective filter with restriction.
Stop the engine. Detach the filter with restriction.
Filter with restriction is clear.
YES NO
Defective filter with restriction.