With Generic Scan Tool

Ignition Coils With Power Output Stages, Checking

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1527 voltage test lamp
- VAG1594 connector test kit
- Wiring diagram

Test requirements

- Respective fuses must be OK.
- Fuel Pump (FP) Relay -J17- must be OK.
- Battery voltage must be at least 11.5 volts.
- All electrical consumers like, for example, lights and rear window heating must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Engine speed (RPM) sensor must be OK. Testing and Inspection
- Camshaft Position (CMP) sensors must be OK. Testing and Inspection
- Ignition switched off.

Test sequence

Checking voltage supply

Vehicles with engine code AWD

- Disconnect 4-pin connector -2- from ignition coil -1- to be checked.
- Measure supply voltage between terminals 1 + 2 and 1 + 4 of disconnected connector using the multimeter.
- Switch on ignition.
Specified value: at least 11.5 V

- Switch ignition off.

If there is no voltage:

- Check wire between 4-pin connector terminal 1 and Motronic Engine Control Module (ECM) Power Supply Relay (main relay) for open circuit according to wiring diagram.
Wire resistance: max: 1.5 Ohms

- Check wires between 4-pin connector and Ground (GND) for open circuit according to wiring diagram.
Terminal 2 and Ground (GND)
Terminal 4 and Ground (GND)
Wire resistance: max: 1.5 Ohms

Vehicles with engine code AWP, AWW

- Remove fuse 32

NOTE: By removing fuse 32, voltage supply to the fuel injectors is interrupted.

Vehicles with engine code AWD

- Connect diode test lamp to terminals 2 + 3 of disconnected connector.

Vehicles with engine code AWP, AWW

- Connect diode test lamp to terminals 2 + 3 of disconnected connector.

Continuation for all vehicles
- Operate starter and test ignition signal from Engine Control Module (ECM).
LED should flicker.
- Switch ignition off.

If LED flickers and voltage supply is OK:
- Replace ignition coils with power output stage:
- Vehicles with engine code AWD, item 3,
- Vehicles with engine code AWP, AWW, item 2.

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If LED does not flicker:
- Check wires

Checking wiring
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Vehicles with engine code AWD

- Check wires between test box and 4-pin connector for open circuit according to wiring diagram.
Cylinder 1 terminal 3 + socket 102
Cylinder 2 terminal 3 + socket 95
Cylinder 3 terminal 3 + socket 103
Cylinder 4 terminal 3 + socket 94
Wire resistance: max: 1.5 Ohms

Vehicles with engine code AWP, AWW