volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Exterior mirrors > < Coding trailer detector control unitJ345
Engine cooling
Engine cooling
Since higher demands are placed on the engine cooling system when a trailer is being towed, the cooling system is uprated in conjunction with factory fitted towing attachments if this is a technical necessity. This is carried out, for example, by installing a more powerful or second radiator fan and/or larger radiator. Vehicles with air conditioning and those prepared for topical climates with air conditioning already have an uprated engine cooling system. On the Passat, a more powerful radiator fan (PR no. 0Y2) can also be factory installed as a single fan. This makes it easier to retrofit a trailer towing system.
The cooling system should also be uprated if a towing attachment is retrofitted and provision for this has not been made in the factory. If this is not done, overheating of the cooling system cannot be ruled out if the engine is placed under high load (gradients, high ambient temperatures, heavy trailer). During conversion, the parts listed in ETKA (electronic parts catalogue) must be used for engine cooling in combination with trailer towing. In addition, the work instructions from the relevant workshop manuals must be followed.
It is only possible to choose not to uprate the cooling system if assurance can be given that the engine will only be placed under medium load, e.g.
t  stay well below the gross combination weight
t  high ambient temperatures are unlikely
t  the vehicle is not driven up long, steep gradients
t  no very long journeys are undertaken
In any case, the coolant temperature gauge must be observed carefully. If the needle of the display moves too far into the hot zone, the speed of the vehicle should be reduced immediately. In an emergency, it may even be necessary to stop and allow the engine to cool down. In this instance, the engine should be allowed to idle for about 2 minutes to avoid any build up of heat.
  Note
t  On vehicles with air conditioning, cooling of the engine can be assisted by switching off the air conditioning system. In this way, there will be an improvement in pulling away and overtaking.
t  If an except is made in uprating the cooling system (i.e. uprating has been dispensed with), the new owner must be informed of this fact when the vehicle is sold.
   

Exterior mirrors > < Coding trailer detector control unitJ345