Skoda Workshop Service and Repair Manuals

Inspecting the voltage supply, control and resistances of the injectors Special tools and workshop equipment required t  Hand multimeter (e.g. -V.A.G 1526 A-) t  Diode test lamp (e.g. -V.A.G 1527 B-) t  Adapter cable set (e.g. -V.A.G 1594 A-) t  Test box -V.A.G 1598/31- Test conditions

l  Fuse no. 35 o.k. l  Earth connections between engine (at clutch housing) and body (below battery) o.k. l  Battery voltage at least 11.5 volts l  Engine speed sender o.k., test → Chapter. l  Fuel pump relay o.k., test → Chapter Test sequence

–  Remove engine cover as follows: t  Release logo -2- and cap -3-. t  Release nuts -4- (5 Nm). t  Pull out oil dipstick -6-. t  Remove engine cover -1- towards the top (do not unscrew cap -5-).

–  Unplug connector -1- of the injection valves -2-. –  Connect up the diode test lamp with adapter cables from -V.A.G 1594 A- to the contacts of the plug for cylinder 1. –  Activate the starter. The diode test lamp must flicker. –  Repeat test on the plug connections for the injection valves on cylinder 2...4. If the diode test lamp does not flicker:

–  Connect the diode test lamp to the plug connection of the injection valve to be checked, contact 1 and earth. –  Activate the starter. The diode test lamp must light up. If the diode test lamp does not light up: –  Check wiring between contact 1 and fuse no. 35 for interruption → Current flow diagrams and Fitting locations. –  if necessary eliminate open circuit. If no fault was detected: –  Switch off ignition. –  Connect test box -V.A.G 1598/31 - to the wiring loom on the engine control unit → Chapter.

–  Check wiring between the test box and the plugs on the injection valves for interruption according to the Current Flow Diagram.

Plug connection on cylinder	Contact	Bush
1	2	88
2	2	87
3	2	85
4	2	86

–  Also check the wires for short-circuits and to positive terminal. If the lines are not found to be faulty:

–  Test the resistance of the injection valves between the contacts.    Specified value: 14…20 Ω If the specified value is not reached: –  Replace the injection valve(s).