SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | 4 cyl. diesel engine with distributor pump | Fuel preparation system Diesel injection | Components and functions: checking | Intake manifold temperature sender: checking

Checking process

–	Connect fault reader -V.A.G 1551- (-V.A.G 1552-). Start engine and select “Address code” 01 to select engine control unit.

Indicated on display:

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

Rapid data transfer                 HELP

Select function XX

Indicated on display:

–	Press keys 0, 0 and 7 for “Display group number 7” and confirm entry with Q key.

Read measured value block

Enter number group values XXX

–

–	Indicated on display:

–	Check the temperature value of the intake manifold which is displayed in display field 3: The temperature should be approx. the ambient temperature.

–	If a realistic reading is not given in field 3 or if a replacement temperature of 136.8 °C is given, the intake manifold temperature sender -G72-- should be checked along with the wiring leading to the switch as follows:

–	Press → key.

–	Press keys 0 and 6 for the “End output” function and confirm input with the Q key.

–	Switch off ignition.

–	Extract the intake manifold temperature sender switch -G72-, Components' fitting locations, → Chapter.

Read measured value block      7       →

15,4°C            15.9°C          16.7°C

–	Connect the manual multimetre between the contacts of the intake manifold sender -G72-.

Specification: see diagram

Scale A shows resistance values for temperature range 0...50 °C, and scale B the values for temperature range 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 specification is not obtained:

–	Replace the intake manifold temperature sender -G72-.

If the specification is obtained:

–	Connect test box -V.A.G 1598/31- to control unit wiring harness. The engine control unit remains disconnected.

–	Check wiring for open circuit between test box and connector using current flow diagram. Contact 1+socket 73 Contact 2+socket 51 Wire resistance: 1,5 Ω Max.

–	Additionally check wires for shorts to one another, to vehicle earth or to battery positive. Specification: ∞ Ω

If no wiring fault is detected:

–	Replace diesel direct injection control unit -J248- → Anchor.

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