SEAT Workshop Service and Repair Manuals

Supplementary heating element -Z35-: checking The supplementary heating element -Z35- with its peripherals (load signal alternator terminal DF, relay for low heating power -J359-, relay for high heating power -J360-, intake manifold temperature sender -G72-, coolant temperature sender -G62-) can be consulted using the engine control unit's self-diagnosis. Check supplementary heating element -Z35- Special tools and workshop equipment required t  Manual multimeter -V.A.G 1526B- t  Multimeter -V.A.G 1715- t  Measuring tool set -V.A.G 1594-

t  Digital potentiometer -V.A.G 1630-

t  Vehicle Diagnosis, Testing and Information System -VAS 5051A- t  → Current flow diagrams, Electrical fault finding and Fitting locations Test requirements l  Intake temperature below 19 °C. l  Coolant temperature below 80 °C l  Vehicle interior temperature below 20 °C approx l  Battery voltage more than 11 V l  Alternator charge not greater than 50% (terminal DF) l  Engine speed above 450 rpm l  Turbine speed of heating 4 l  Turn the control for the interior temperature as far as it will go in the heating range Test sequence When the specifications for intake and coolant temperature are not met, it is necessary to duplicate the following test conditions. The intake manifold pressure sender and the intake air temperature sender are combined in a housing located in the intake manifold.

Connect digital potentiometer -V.A.G 1630- to the intake manifold temperature sender switch -G72- between pins 1+4.

Specification: see diagram The area A indicates the resistance values for the range of temperatures from 0...50 °C and the area B, the range of temperatures from 50...100 °C. Example: t  10 °C corresponds to a resistance value of 3,500...4.000 Ω t  80 °C corresponds to a resistance value of 275....375 Ω → Rep. Gr.23

–  Connect digital potentiometer -V.A.G 1630- to the coolant temperature sender -G62- connector, between pins 1+2.

Specification: see diagram The area A indicates the resistance values for the range of temperatures from 0...50 °C and the area B, the range of temperatures from 50...100 °C. Example: t  40 °C corresponds to a resistance value of 1,000...1.500 Ω t  80 °C corresponds to a resistance value of 275...375 Ω

–	Using the current clamp, connect the multimeter -V.A.G 1715- to the cable of the secondary heating element -Z35-

–

Adjust multimeter -V.A.G 1715- for testing amperes. Once the engine has been started and some 10 seconds have gone by, the diesel direct injection control unit -J248- enables the functioning of the heating element for secondary heating -Z35-. The engine control unit connects and disconnects the three heating elements by stages via the relays.

–	Leave the engine on and running at idling speed.

In vehicles with air conditioning, it will have to be disconnected.

Under established test conditions, the current supply for the heating element of the additional heating -Z35- is approx. 38.9 A or even higher.

If no fault in lines is detected:

–	Replace the heating element of the additional heating -Z35- → Chapter

–	Interrogate fault memory → Rep. Gr.01