SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | Direct injection and preheating system with distributor pump | Fuel preparation system Diesel injection | Components and functions: check | Temperature transmitter in the inlet manifold: check

Temperature transmitter in the inlet manifold: check

Special tools and workshop equipment required

t	Fault reader -V.A.G 1551- or vehicle system checker -V.A.G 1552- with cable -V.A.G 1551/3B-

t	Checking box -V.A.G 1598/22-

t	Manual multimeter -V.A.G 1526 A- or multimeter -V.A.G 1715-

t	Auxiliary measuring set -V.A.G 1594 C-

t	Current circuit diagrams

Checking process

–	Connect the -V.A.G 1551- (-V.A.G 1552-), and using the corresponding “direction code” 01, select the control unit for engine electronics. When doing this, the engine must be idling: (Fault reader: Turn on and select the control unit for engine electronics → Chapter).

Indication on the display:

–	Press the keys 0 and 8 for the function “Read measurement value block” and confirm with Q.

Fast data transmission              HELP

Select the function XX

Indication on the display:

–	Press the keys 0, 0 and 7 for “Indication group number 7” and confirm with Q.

Read measurement value block

Introduction value group number XXX

Indication on the display:

–	If in field 3 the indication is not realistic or a supplementary temperature is given of 136,8 °C, the temperature transmitter of the inlet manifold must be checked, and also the cabling to the transmitter, proceeding as follows:

–

Press →.

–	Press the keys 0 and 6 for the function “End data transmission” and confirm with Q.

–	Turn off the ignition.

Read measurement value block 7        ->

15,4 ºC              15,9 ºC     16,7 ºC

–	Extract the connector -1- from the temperature transmitter of the inlet manifold -2-.

–	Measure the resistance between the contacts of the transmitter -2-.

Theoretical value: see diagram

Area -A- indicates the resistance values for the temperature margin 0...50 ° and area -B-, the values for the temperature margin 50...100 °C.

Examples:

t	30 °C corresponds to a resistance of 1.500...2.000 Ω

t	80 °C corresponds to a resistance of 275...375 Ω

If the theoretical value is not reached:

–	Replace the temperature transmitter of the inlet manifold -G72-).

If the theoretical value is achieved:

–	Connect the -V.A.G 1598/22- checking box to the cable harness of the control unit.

–	Check for breakage in the cables between the checking box and the connector, following the current circuit diagram.

Contact 1+female 13

Contact 2+female 25

Cable resistance: 1,5Ω max.

–	Additionally, check the cables for short circuiting between them, to ground and to battery positive.

Theoretical value: ∞ Ω

If no fault is found in the cables:

–	Replace the engine control unit -J248- → Chapter.

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