Skoda Workshop Service and Repair Manuals

Testing injection valves Test control Special tools and workshop equipment required t  Test box -V.A.G 1598/31- t  Hand multimeter (e.g. -V.A.G 1526 A-) t  Voltage tester (e. g. -V.A.G 1527 B-) t  Adapter cable set (e.g. -V.A.G 1594 A-) t  Current flow diagram Test conditions

l  Fuse 32 must be in proper order. l  Earth connections between engine (at clutch housing) and body (below battery) o.k. l  Battery voltage at least 11 V. l  Engine speed sender o.k., test → Chapter. l  Fuel pump relay o.k., test → Chapter. Test sequence –  Remove engine cover.

–  Unplug connector -1- of the injection valves -2-. –  Connect with the adapter cables from the -V.A.G 1594 A- voltage tester to the contact of the plug for cylinder 1. –  Activate the starter. The LED must flash. –  Repeat the test on the plugs for the injection valves on cylinder 2...4. If LED does not flash: –  Switch off ignition.

–  Connect the test box -V.A.G 1598/31- to the wiring loom of the engine control unit → Chapter.

–  Check wiring between the test box and the plugs from the injection valves for interruption according to the current flow diagram.    Plug on cylinder 1, contact 2+bush 88    Plug on cylinder 2, contact 2+bush 87    Plug on cylinder 3, contact 2+bush 85    Plug on cylinder 4, contact 2+bush 86    Cable resistance: max. 1.5 Ω –  Also check the wires for short-circuits and to positive terminal. Specified value: ∞ Ω –  Connect voltage tester -V.A.G 1527 B- according to the table:

Contact to connector plug	Measure against
1	Engine mass

–  Operate starter briefly (while doing so, the engine can also start). t  The LED must light up Diode does not light up: –  Check cable connection between contact 1 and fuse for injection valves for interruption → Current flow diagrams and Fitting locations. –  if necessary eliminate open circuit. Diode lights up: –  Check the actuation of the injection valves. Check the resistance of the injection valves

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