With Manufacturer's Scan Tool

Ignition Coils With Power Output Stage, Checking

NOTE:
- Ignition coils and final output stages are one component and cannot be replaced individually.
- The ignition coil primary resistance cannot be measured.

Special tools and equipment
- Test box VAG1598/31
- Multimeter Fluke 83 or equivalent
- Adapter set VAG1594
- VAG1527B Voltage tester
- Wiring diagram

Check conditions
- Battery voltage at least 11.5 V
- Engine speed sender OK, checking. Engine Speed (RPM) Sensor, Checking
- Camshaft Position (CMP) sensor OK, checking. Camshaft Position (CMP) Sensor, Checking






- All fuses must be OK.






Checking voltage supply
- Disconnect the 6-pin connector from the ignition coils with power output stages -N70-, -N127-, -N291-, -N292- (arrow).






- Using multimeter and adapter cables from VAG1594, measure supply voltage between contacts 1 + 6 of disconnected connector.
- Switch on ignition.
Specification: min. 11.5 V

- Switch off ignition.

If no voltage is present:
- Check wiring for open circuit between 6-pin connector contact 6 and Motronic Engine Control Module (ECM) power supply relay -J271-using wiring diagram.
Wire resistance: max. 1.5 Ohms

- Check wire between 6 pin connector contact 1 and Ground for open circuit according to wiring diagram.
Wire resistance: max. 1.5 Ohms

If there is no malfunction in the supply voltage:
- Check activation.

Checking activation

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






- Remove fuse 32

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

- Disconnect the 6-pin connector from the ignition coils with power output stages -N70-, -N127-, -N291-, -N292- (arrow).






- Connect VAG1527B Voltage tester with adapter cables from VAG1594 to
terminals 1 + 2 (ignition output 1)
terminals 1 + 3 (ignition output 2)
terminals 1 + 4 (ignition output 3)
terminals 1 + 5 (ignition output 4)
of disconnected connector.

- Get a 2nd person to operate starter and check the ignition signal from engine control module.
LED must flicker
- Switch off ignition.

If the LED flickers and there is voltage between contacts 1 + 6:
- Replace ignition coils with output stage

The LED does not flicker:
- Remove wiper arms and cowl panel.






- Connect test box VAG1598/31 to control module wiring harness. The engine control module remains disconnected.






- Check wiring between test box and 6-pin connector for open circuit using wiring diagram.
Cylinder 1 contact 2 + socket 102
Cylinder 2 contact 3 + socket 95
Cylinder 3 contact 4 + socket 103
Cylinder 4 contact 5 + socket 94
Wire resistance: Max. 1.5 Ohms

- Also check wires for short to one another and to positive and Ground.
Specification: Infinity Ohms

If wiring is OK and voltage was present between contacts 1 + 6:
- Replace engine control module.