Checking the ignition coil (VW Polo 3)

Contents: Checking activation ↓ Checking the wires ↓ Checking the resistance of the…↓

1. Disconnect the four-pin wiring connector from the ignition coil (arrow) (Fig. 4.46).

2. Fuse No.34 must be in working condition (Fig. 4.47).

3. Connect a multimeter to check the voltage using the wires from VAG 1594 to contacts 2 and 4 of the wiring connector (Fig. 4.48).

4. Turn on the ignition. Specification value: minimum 11 V.

5. Turn off the ignition.

6. If there is no voltage, remove the cover on the left in the engine compartment and connect the VAG 1598/31 tester to the wiring harness of the engine control unit (on the left in the engine compartment) (fig. 4.32). The control unit must remain disconnected.

7. Check the wire between contact 2 of the four-pin harness connector and the relay support for open circuit (Fig. 4.49). Specification resistance: 1.5 ohms.

7. Check the wire between contact 2 of the four-pin harness connector and the relay support for…

8. Check the wire between terminal 4 of the four-pin harness connector and ground for open circuit. Specification: 1.5 ohms.

Checking activation

9. Remove the engine cover (fig. 4.44).

10. Disconnect the wiring connectors (arrows) from the injectors (Fig. 4.50).

10. Connect the VAG 1527 diode tester using the wires from the VAG 1594 to contacts 1 and 4 (output 1) and to contacts 2 and 3 (output 1) of the disconnected connector (Fig. 4.48).

11. Start the engine with the starter and check the ignition signal from the engine control unit. The tester lamp should flash.

12. Turn off the ignition.

13. If the tester lamp flashes and there is voltage between contacts 2 and 3, replace the ignition coil.

[The original can be seen on the portal VWMANUAL]

14. If the tester light does not blink, check the wiring.

Checking the wires

15. Remove the cover on the left in the engine compartment and connect the VAG 1598/31 tester to the engine control unit wiring harness (fig. 4.32). Check the wires between the tester and the connector for open circuit: pin 1 + socket 102, pin 2 + socket 103. Wire resistance: max. 1.5 ohms.

16. Additionally, check for short circuits between wires.

Specification resistance: ∞ Ohm.

17. If no faults are found in the wiring and there is voltage between terminals 2 and 4, replace the engine control unit.

Checking the resistance of the secondary coil

18. Check the resistance between the four terminals: cylinder 1 and cylinder 4, cylinder 2 and cylinder 3 (Fig. 4.51). Specific resistance: 4-6 kOhm (at 20°C).