With Generic Scan Tool
Ignition coils with power output stages, checking
Recommended special tools and equipment
- V.A.G1526A hand multimeter
- V.A.G 1527 B Voltage Tester
- V.A.G1594A connector test kit
- V.A.G1598/31 test box
NOTE: The ignition coil and power output stage are combined in one complete component.
Test requirement:
- Fuses for engine electronics OK
Procedure
- Remove engine cover (arrows).
- Start engine and let run at idle.
Recognize a non-functional or misfiring cylinder as follows:
- Disconnect connectors from fuel injectors in sequence with engine running and observe engine operation.
or
- Compare spark plugs of all cylinders to each other. Check electrodes for carbon fouling.
If faulty cylinder is recognized:
- Switch spark plug from faulty cylinder with one from another cylinder.
If malfunction follows the spark plug:
- Replace spark plug.
If malfunction remains at original cylinder:
- Switch ignition coil from faulty cylinder with one from another cylinder.
If malfunction follows the ignition coil:
- Replace ignition coil.
Checking Ground (GND) connections
- Disconnect the 4-pin harness connector -1- at the ignition coil -2-.
- Connect e.g. V.A.G 1527 B voltage tester as follows:
Harness connector Measure to
Terminal
2 B+
4 B+
- LED must light up.
If LED does not light up:
- Check the wire connections for open circuit.
Specified value: Wire resistance max 1.5 Ohms
- If necessary, repair wire connection.
If LED lights up:
Checking voltage supply
- Connect multimeter for voltage measurement as follows:
Harness connector Measure to
Terminal
1 Engine Ground (GND)
- Switch ignition on.
Specified value: approx. battery voltage
- Switch ignition off.
If specified value is obtained:
- Check activation of power output stages.
If specified value is not obtained:
- Remove rubber seal for plenum chamber cover.
- Remove plenum chamber cover -1- toward front (arrows).
- Pry off both covers -3- using a screwdriver.
- Loosen hex-nuts -4- by several turns.
- Loosen wiper arm -2- from wiper axle by lightly tilting.
- Remove hex nuts completely and remove wiper arms.
- Disconnect securing clips -1- and remove cowl grill -5-.
- Remove cover for E-box, plenum chamber (arrows).
- Pry off Engine Control Module (ECM) retaining bracket (arrows) using a screwdriver and set control module aside.
- If installed, unclip Transmission Control Module (TCM) retaining bracket and set control module aside.
- Disconnect voltage supply relay -2-.
- Perform the following tests marked with dots:
- Check wire connection from relay carrier in E-box, plenum chamber, position 3, terminal 8 to harness connector at ignition coil terminal 1.
- Check Motronic Engine Control Module (ECM) voltage supply relay -J271-.
Checking activation of power output stages
- Harness connectors at ignition coils disconnected
- Disconnect all harness connectors from all fuel injectors.
NOTE: Fuel must not be injected during the test to avoid damaging catalytic converter. Connectors must therefore be disconnected from fuel injectors.
- Connect e.g. V.A.G 1527 B voltage tester to connector terminals 2 and 3.
- Operate starter briefly.
- LED must blink (brief blink signal).
- Switch ignition off.
If LED does not blink:
- Connect test box to wiring harness of Engine Control Module (ECM) ECM is not connected. Test Box, Connecting For Wiring and Component Test
- Check the following wire connections for open circuit according to wiring diagram:
Harness connector V.A.G1598/31 test box
Terminal Socket
3 (Cyl. 1) 102
3 (Cyl. 2) 95
3 (Cyl. 3) 103
3 (Cyl. 4) 94
Specified value: Wire resistance max 1.5 Ohms
- Check wires for short circuit to each other as well as to B+ and Ground (GND).
Specified value: Infinite Ohms (no continuity)
- If necessary, repair wire connection.
If no malfunctions are found in wires:
- Replace the combined component, ignition coil with power output stage.
Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check DTC memory. Mode 3: Check DTC Memory
2. If necessary, erase DTC memory. Mode 4: Reset/Erase Diagnostic Data
3. Generate readiness code. Readiness Code, Generating
- End diagnosis and switch ignition off.