With Generic Scan Tool

Ignition Coils With Power Output Stages (Vehicles with engine code BDF), checking

NOTE: Ignition coils and power output stages are one component and cannot be replaced separately.

Special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1527 voltage test lamp
- VAG1594 connector test kit
- VAG1598/31 test box
- Wiring diagram

Test requirements







- The respective fuses of ignition coils must be OK.
- Motronic Engine Control Module (ECM) Power Supply Relay -J271-must be OK, check.
- 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.
- For vehicles with automatic transmission, selector lever must be in position -P-or -N-.
- 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, checking.
Testing and Inspection

- Camshaft Position (CMP) sensors must be OK, checking.
Testing and Inspection

- Ignition switched off.

Test sequence







- Remove fuse 29 from fuse holder.

NOTE: By removing fuse 29, voltage supply to the fuel injectors is interrupted.

- Remove engine cover.







- Disconnect connector from ignition coils 1 to 6.

NOTE: Before disconnecting harness connectors, mark allocation to component.

Checking voltage supply







- Measure supply voltage between terminals 1 + 3 and 2 + 3 of disconnected connector using the multimeter and adapter cables.
- 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 3 and Motronic Engine Control Module (ECM) Power Supply Relay -J271- 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 1 and Ground (GND)
Terminal 2 and Ground (GND)
Wire resistance: max: 1.5 Ohms

If there is no malfunction in voltage supply:
- Check activation.

Checking activation







- Using adapter cables, connect voltage tester (VAG1527) to Terminals 4 + engine Ground (GND) of disconnected connector for cylinder 1.
- Operate starter and test ignition signal from Engine Control Module(ECM)
LED should flicker.
- Repeat test at connectors for fuel injectors 2 through 6.
- Switch ignition off.

If LED flickers and voltage supply is OK:
- Replace respective ignition coil with power output stage, 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







- Check wires between test box and 4-pin connector for open circuit according to wiring diagram.
Wire resistance: max: 1.5 Ohms










- Also check wires for short circuit to each other.
Specified value: Infinity Ohms

If there is no malfunction in wire connections:
- Replace Engine Control Module (ECM).