With Manufacturer's Scan Tool

Ignition Coils With Power Output Stages, Checking

Special tools and equipment







- VAG1526A
- VAG1527B
- VAG1594A
- VAG1598/31

Test sequence

NOTE: The ignition coil and power output stage are combined in one complete component.







- Remove engine cover (arrows).

Identify an inoperative or misfiring cylinder as follows:
- Test misfire detection. Testing and Inspection

If misfires are detected:
- Continue checking indicated cylinder see "If the faulty cylinder is recognized".

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 soot on electrodes.

If the faulty cylinder is recognized:
- Replace spark plug of faulty cylinder with one from another cylinder.

If malfunction moves with spark plug:
- Replace spark plug.

If malfunction remains in same cylinder:
- Replace ignition coil from faulty cylinder with one from another cylinder.

If malfunction moves with ignition coil:
- Replace ignition coil.

Test ground (GND) connection







- Disconnect 4-pin connector -1- from ignition coil -2-.







- Connect voltage tester V.A.G 1527 B as follows:

Connector terminal Measure to
2 Battery positive (B+)
4 Battery positive (B+)

- LED should light up.

If the LED does not light up:
- Check wiring connections.

If the LED lights up:
- Check the power supply.

Checking power supply
- Fuses for engine electronics OK







- Connect multimeter as follows to measure voltage:

Connector terminal Measure to
1 Engine ground (GND)

- Switch ignition on.
- Specified value: approx. battery voltage (B+)

If specified value is obtained:
- Check activation of power output stages.

If specified value is not obtained:







- Disconnect power supply relay -1- under cover on left bulkhead.

NOTE: To remove protective cover on vehicles with relay carrier on bulkhead, disconnect and lower. If necessary, disconnect connector from mass air flow sensor.

- Perform following tests, specified by below:







- Check wire connections from relay carrier under cover on left bulkhead, contact 2 to contact 1 on ignition coil.
- Check Motronic Engine Control Module (ECM) power supply relay -J271-. Motronic ECM Power Supply Relay -J271-, Checking

If specified value is obtained:
- Check activation of power output stage.

Checking activation of power output stages
- Pull connector off all four fuel injectors.

NOTE: Fuel must not be injected during test to avoid damaging catalytic converter. Connectors must be disconnected from fuel injectors.







- Remove 4-pin connector -1- at ignition coil -2-.







- Connect VAG1527B voltage tester to connector terminals 2 and 3.
- Operate starter briefly.
- LED must blink (brief blink signal).

If LED does not flash:
- Connect test box V.A.G 1598/31 to wiring harness for ECM; do not connect ECM. Electrical Testing Using VAG1598/31 Test Box







- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:

Harness connector VAG1598/31 test box
Terminal Socket
3 (Cyl. 1 ) 102
3 (Cyl. 2) 95
3 (Cyl. 3) 103
3 (Cyl. 4) 94

- Repair open circuit or short circuit if necessary.

If no malfunctions are found in wires:
- Replace combined component, ignition coil with power output stage