With Generic Scan Tool
Checking ignition coils with power output stages (Vehicles with engine code AVH, AZG, BDC)
Note: Ignition coils and power output stages are one component and cannot be replaced individually.
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 such as, for example, lights and rear window defroster 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. Testing and Inspection
- Camshaft Position (CMP) sensor must be OK. Testing and Inspection
- Ignition switched off.
Test sequence
- Disconnect the 6-pin connector from the power output stage for ignition coils (arrow).
Checking voltage supply
- Use multimeter and adapter cables to measure voltage supply between terminals 1 + 6 of the disconnected connector.
- Switch on ignition. Specified value: at least 11.5 V
- Switch ignition off.
If there is no voltage:
- Check wire between 6-pin connector terminal 6 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 6-pin connector terminal 1 and Ground (GND) for open circuit according to wiring diagram. Wire resistance: max. 1.5 ohms
If there is no malfunction in voltage supply:
- Check activation.
Checking activation
WARNING: Do not touch ignition coil connecting parts or adapter cables during the following test.
- Remove fuse 32 from fuse holder.
Note: By removing fuse 32, voltage supply to the fuel injectors is interrupted.
- Using adapter cables, connect voltage tester (VAG1527) to
Terminals 1 + 2 (ignition output 1)
Terminals 1 + 3 (ignition output 2)
Terminals 1 + 4 (ignition output 3)
Terminals 1 + 5 (ignition output 4) of disconnected connector.
- 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 coil with power output stage (-N70-, -N127-, -N291-, -N292-), item 2.
- Erase DTC memory of Engine Control Module (ECM), 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 6-pin connector for open circuit according to wiring diagram.
Cylinder 1 terminal 2 + socket 102
Cylinder 2 terminal 3 + socket 95
Cylinder 3 terminal 4 + socket 103
Cylinder 4 terminal 5 + socket 94
Wire resistance: max. 1.5 ohms
- Also check wires for short circuit to each other.
Specified value: Infinite Ohms
If there is no malfunction in wire connections:
- Replace Motronic Engine Control Module (ECM) -J220-.