Ignition Coil: Testing and Inspection

Ignition Coils With Power Output Stage, Checking

The following procedure is used to diagnose Ignition Coils with Power Output Stage N70, N127, N291, N292, N323, N324.

Special tools, testers and auxiliary items required
- Multimeter.
- Diode test lamp.
- Wiring diagram.

Test requirements
- The Motronic Engine Control Module (ECM) J220 fuses OK.
- Motronic Engine Control Module (ECM) Power Supply Relay J271 OK.
- Engine Speed (RPM) Sensor G28 OK.
- Camshaft Position (CMP) Sensor G40 OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.

Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis

Start diagnosis







- Disconnect the Ignition Coils with Power Output Stage electrical harness connectors -1 through 6 - from the Ignition Coils with Power Output Stage.

Checking voltage supply
- Switch the ignition on.







- Using a Multimeter, check the Ignition Coil electrical harness connector terminals 1 to 4 for voltage.

Specified value: battery voltage.
- Switch the ignition off.

If the specified value was not obtained:
- Check the Ignition Coil electrical harness connector terminal 1 to battery (+) connection 1 for an open circuit, short circuit to Battery (+) or Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If the specified values were obtained:

Checking activation

CAUTION: Do not touch the Ignition Coils connecting parts or adapter cables during the following test.

- Disable the power supply to the Fuel Injectors by removing Fuse SB6.







- Using a diode test lamp, check the Ignition Coil electrical harness connector terminals 2 to 3 for voltage.
- Operate the starter.

The LED should flicker.
- Switch the ignition off.

If the LED flickers and the voltage was OK:
- Replace the faulty Ignition Coils with Power Output Stage.

If the LED does not flicker:

Checking wiring
If the manufacturers test box is being used. Perform the following step.
- Install the test box VAG1598/31.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220.







- Using a Multimeter, Check the Ignition Coil electrical harness connector to the Motronic Engine Control Module (ECM) J220 electrical harness connector for resistance.

Ignition Coils with Power Motronic Engine Control Module (ECM) J220
Output Stage electrical harness electrical harness connector terminal
connector terminal or test box socket
N70/4 102
N127/4 110
N291/4 94
N292/4 111
N323/4 103
N324/4 95

Specified value: 1.5 Ohms Max.

If the specified value was not obtained:
- Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).
- Check the wiring connection for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If the specified values were obtained:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.

If the DTC does not return:
Repair complete, Generate readiness code. Readiness Code
- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- Assembly is performed in the reverse of the removal.

Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.

End of diagnosis