With Generic Scan Tool

Checking ignition coil (Vehicles with engine code AEG)

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

Test requirements






- The respective fuses of Ignition Coil -N152- 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.
- 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.
- Camshaft Position (CMP) sensor must be OK
- Ignition switched off.

Test sequence





- Disconnect 4-pin connector from Ignition Coil -N152- (arrow).

Checking voltage supply





- Connect multimeter to terminals 2 + 4 of the disconnected connector for voltage measurement.
- 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 2 and relay carrier for open circuits according to wiring diagram. Wire resistance: max: 1.5 ohms
- Check for open circuit in wire between 4-pin connector terminal 4 and Ground (GND) according to wiring diagram. Wire resistance: max: 1.5 ohms

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

Checking activation

CAUTION! 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 + 4 (ignition output 1),
Terminals 3 + 4 (ignition output 2), 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 -N152-
- 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.






- Check wires between test box and 4-pin connector for open circuit according to wiring diagram.
Terminal 1 + socket 71
Terminal 3 + socket 78
Wire resistance: max: 1.5 ohms

- Also check wires for short circuit to each other. Specified value: infinite ohms

If no malfunctions are found in the wires and there was voltage between terminal 2 + 4:

- Replace Motronic Engine Control Module (ECM) -J220-

Checking secondary resistances






- Check secondary resistances at terminal 4 between:
Cyl. 1 + Cyl. 4
Cyl. 2 + Cyl. 3
Specified value: 4,0... 6.0k ohms

If specified values are not obtained:

- Replace Ignition Coil -N152-.
- 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