With Manufacturer's Scan Tool
Ignition Coils With Output Stages, Checking
Special tools and equipment
- VAG 1526 A
- VAG 1527 B
- VAG 1594 A
- VAG 1598/31
Test sequence
NOTE: The ignition coil and the output stage are combined in a common component.
Identify an inoperative or misfiring cylinder as follows:
- Test misfire detection. Testing and Inspection
If misfires are detected:
- Continue checking indicated cylinder if faulty cylinder has been detected.
If no misfires were detected:
- Disconnect connectors from injectors in sequence with engine running, and observe how engine runs.
or
- Compare spark plugs of all cylinders with each other and check for carbon on electrodes.
If the faulty cylinder has been identified:
- Replace spark plug of faulty cylinder with one from another cylinder.
If the malfunction moves with the spark plug:
- Replace spark plug.
If the malfunction remains in the same cylinder:
- Replace ignition coil from faulty cylinder with one from another cylinder.
If the malfunction moves with the ignition coil:
- Replace ignition coil.
Test Ground connection
- Disconnect cover -1- on left in engine compartment.
- Unbolt coolant expansion tank (arrow).
- Disconnect electrical wiring to Engine Coolant Level (ECL) warning switch -F66- on bottom of expansion tank.
- Lay coolant expansion tank with connected coolant hoses -1- to -3- aside.
- Disconnect cover -1- on right in engine compartment.
- Remove bolts (arrows).
- Disconnect solenoid valve for Evaporative Emission (EVAP) canister purge -N80- -1- from air duct.
- Remove air duct -2-.
- Remove air filter housing (arrows).
- Disconnect connector -1- at mass air flow sensor.
- Remove air duct hose -2- together with mass air flow sensor.
- Remove bolts (arrows) on right cylinder head.
- Disconnect 4-pin connectors -1- to -3- on ignition coils.
- Remove bolts (arrows) on left cylinder head.
- Disconnect 4-pin connectors -4- to -6- on ignition coils.
- Connect voltage tester VAG1527 B as follows:
Connector Measure to
terminal
2 Battery positive
4 Battery positive
- LED should illuminate.
If the LED does not illuminate:
- Check wiring connections.
If the LED illuminates:
Checking power supply
Test requirements:
- Fuses for engine electronics OK.
- Connect multimeter as follows to measure voltage:
Connector Measure to
terminal
1 Engine ground
- Switch ignition on.
- Specified value: approx. battery voltage.
If specified value is attained:
- Check actuation of power output stages.
If specified value is not attained:
- Pull off rubber seal of plenum chamber cover.
- Remove plenum chamber cover -1- toward front (arrows).
- Pry off both trim caps -3- with a screwdriver.
- Undo hex nuts -4- a few turns.
- Release wiper arms -2- from pivot shaft by tilting them slightly.
- Remove hex nuts completely and remove wiper arms.
- Disconnect retaining clips -1- and remove air cowl grille -5-.
- Remove cover for electronics box (plenum chamber) (arrows).
- Lift off engine control module retaining clip using a screwdriver (arrow) and move control module to side.
- If installed, unclip transmission control module retaining clip and place control module on one side.
- Disconnect power supply relay -2-.
- Perform following tests (marked with dots).
- Check the wiring of relay carrier, electronics box, plenum chamber, position 2, terminal 8, to connector of ignition coil terminal 1.
- Check power supply relay for Motronic Engine Control Module (ECM) power supply relay -J271-.
Checking Actuation Of Power Output Stages
- Connectors disconnected from ignition coils.
- Disconnect connectors from all injectors.
NOTE: It is important to make sure that no fuel is injected during the test, as this would damage the catalytic converter. The connectors on the injectors must be disconnected.
- Connect voltage tester VAG1527 B to terminals 2 and 3 of connector.
- Operate starter briefly.
- LED test light should flash (very brief flashes).
If LED does not flash:
- Connect test box VAG1598/31 to wiring harness for engine control module; do not connect engine control module. Wiring and Component Testing Using VAG1598/31 Test Box
- Check for open circuit and short to positive or ground in following wiring connections:
Connector Test box VAG 1598/31
terminal Socket
3 (cyl. 1) 102
3 (cyl. 2) 110
3 (cyl. 3) 94
3 (cyl. 4) 103
3 (cyl. 5) 111
3 (cyl. 6) 95
- Repair any open/short circuit as necessary.
If no wiring malfunction is detected:
- Replace common component ignition coil with power output stage.