Ignition Coil: Testing and Inspection

Ignition Coils With Power Output Stages, Checking

Special tools and equipment






- VAG1526A
- VAG1527B
- VAG1594A
- VAG1598/31

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

- Recognize a non-functional or misfiring cylinder as follows:

NOTE: Non-functioning or misfiring cylinders are recognized via output Diagnostic Test Mode (DTM).

- Disconnect connectors from fuel injectors in sequence with engine running and observe engine operation.

or

- Compare spark plugs from all cylinders to each other. Look for fouled electrodes.

If faulty cylinder is recognized:
- Switch spark plug from faulty cylinder with one from another cylinder.

If malfunction follows the spark plug:
- Replace spark plug.

If malfunction remains at original cylinder:
- Switch ignition coil from faulty cylinder with one from another cylinder.

If malfunction follows the ignition coil:
- Replace ignition coil.

If malfunction remains at original cylinder:

Check Ground (GND) connection
- Remove the 4-pin connector at ignition coil.






- Connect VAG1527B voltage tester as follows:

Harness connector Measure to
Terminal
2 B+
4 B+

- LED must light up.

If LED does not light up:
- Check wire connections.

If LED lights up:

Checking voltage supply






- Connect multimeter for voltage measurement as follows:

Harness connector Measure to
Terminal
1 Engine Ground (GND)

- Switch ignition on.
- Specification: approx. battery voltage

If specified value is not obtained:
- Check wire connections.

- Check Motronic Engine Control Module (ECM) power supply relay -J271-. Motronic Engine Control Module (ECM) Power Supply Relay -J271

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 the test to avoid damaging catalytic converter. Connectors must therefore be disconnected from fuel injectors.

- Remove the 4-pin connector at ignition coil.






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

If specified values are not obtained:
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Wiring and Component 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 the combined component, ignition coil with power output stage.