With Manufacturer's Scan Tool

Ignition coils with power output stage, checking

NOTE:
- Ignition coils and output stages are a combined unit.
- The ignition coil primary resistance cannot be measured.

Special tools and equipment
- VAG1598/22 test box
- Multimeter (Fluke 83 or equivalent)
- VW1594 adapter set
- VAG1527B voltage tester
- Wiring diagram

Test requirements
- Battery (B+) voltage at least 11.5 V
- Camshaft Position (CMP) sensor -G40- OK. Testing and Inspection
- Engine speed (RPM) sensor -G28- OK. Testing and Inspection

Test procedure






- Disconnect 4-pin harness connector from ignition coil output stage (arrow).

Checking voltage supply

Test requirements





- Fuse 29 OK






- Using multimeter and adapter cables from VW1594, measure supply voltage between terminals 2 + 4 of disconnected harness connector.
- Turn on ignition.
Specified value: min. 11.5 V

- Turn off ignition.

If no voltage is present:






- Check wiring between 4-pin harness connector terminal 2 and relay plate for open circuit according to wiring diagram.
Wire resistance: max. 1.5 ohms

- Check wiring between 4-pin harness connector terminal 4 and Ground (GND) for open circuit according to wiring diagram.
Wire resistance: max. 1.5 ohms

Checking activation

WARNING! During the following test do not touch the connecting parts of the ignition coils or test cables.






- Remove fuse No. 32 from fuse holder.

NOTE: Removing fuse 32 interrupts the voltage supply to the injectors.






- Connect VAG1527B voltage tester with adapter cables from VW1594 to
- Terminals -1- + -4- (ignition output 1), and
- Terminals -3- + -4- (ignition output 2) of disconnected harness connector.

- Operate starter and check ignition signal from Engine Control Module (ECM).
LED must flicker.

- Turn off ignition.

If the LED flickers and there is voltage between terminals -2- + -4-:
- Replace ignition coil -N-, -N128-. Service and Repair

If the LED does not flicker:
- Check wiring.

Checking wiring
- Remove wiper arms and plenum chamber cover.






- Connect VAG1598/22 test box to control module wiring harness connector.






- Check wiring between test box and 4-pin harness connector for open circuit according to wiring diagram.
- Terminal 1 + socket 71
- Terminal 3 + socket 78
Wire resistance: max. 1.5 ohms

- Also, check if wires are shorted together.
- Terminal -3- + socket 71
Specified value: Infinity ohms

If no malfunction is found in the wiring and voltage was present between terminals -2- + -4-:
- Replace Engine Control Module (ECM).

Checking secondary winding






- Check secondary winding on terminal 4 between
- Cyl. 1 + Cyl. 4
- Cyl. 2 + Cyl. 3
Specified value: 4.0-6.0K ohms (at 20°C)

If the specified values are not attained:
- Replace ignition coils -N-, -N128-. Service and Repair