Skoda Workshop Service and Repair Manuals

Test control Special tools and workshop equipment required t  Test box -V.A.G 1598/31- or -V.A.G 1598/22- t  Handheld multimeter, e.g. -V.A.G 1526 B- t  Diode test lamp, e.g. -V.A.G 1527- t  Measuring tool set, e.g. -V.A.G 1594 C- t  Current flow diagram t  Extractor -T 10094 A- Test conditions

l  Fuse 35 must be OK l  Earth connections between the engine (on gearbox housing) and body (under battery) are o.k. l  Battery voltage at least 11.5 V. l  Engine speed sender o.k.; check → Chapter. l  The hall sender must be OK, test it → Chapter. l  Fuel pump relay OK Test sequence Engines with engine identification characters AUA, AUB, BBY, BBZ, BKY –  Remove engine cover with air filter → Chapter. Engines with engine identification characters AUA, AUB

–  Unplug the 4-pin connector -arrow- from the ignition transformer. Engines with engine identification characters BBY, BBZ, BKY –  Slightly pull out all the ignition coils with the extractor -T 10094 A- and disconnect the plug connections → Chapter. Engines with engine identification characters BUD –  Engine cover → 1.4/55; 1.4/59; 1.4/74 Engine - Mechanics → Rep. Gr.15 –  Slightly pull out all the ignition coils with the extractor -T 10094 A- and disconnect the plug connections → Chapter. Continued for all engines

–  Unplug connector -arrows- of the injectors.

–  Connect up the diode test lamp to the contacts of the plug for cylinder 1. –  Actuate the starter and check the power supply to the injection valve of cylinder 1. LED must flash. –  Repeat the test on the injection valves of cylinders 2 to 4 in sequence. –  Switch off ignition. If the LED does not light up on any cylinder:

–  Connect the diode test lamp to the plug connection on cylinder 1, contact 1 and earth. –  Actuate the starter and check the power supply to the injection valve of cylinder 1. LED must flash. –  Repeat test on the plug connections for the injection valves on cylinder 2 to 4. If the LED does not flash: –  Switch off ignition. –  Check the cable between the 2-pin plug contact 1 and the fuel pump relay -J17- for interruption according to the current flow diagram → Current flow diagrams and Fitting locations. Cable resistance: max. 1.5 Ω If the LED does not light up on one or more cylinders: –  Connect test box - V.A.G 1598/31- or -V.A.G 1598/22 - to the wiring loom of the control unit → Chapter. The engine control unit is not connected here.

–  Check wiring between the test box and the 2-pin plugs of the injection valves for interruption according to the current flow diagram → Current flow diagrams and Fitting locations. Cable resistance: max. 1.5 Ω –  Test the cables for short circuiting with each other. Specified value: ∞ Ω –  Check wiring between contacts 1 of the plug connection on the injection valves for interruption of each other. Cable resistance: max. 1.5 Ω