With Generic Scan Tool
Ignition Coils With Power Output Stages, Checking
Recommended special tools and equipment
- VAG1526A multimeter
- V.A.G 1527 B Voltage Tester
- VAG1594A connector test kit
- VAG1598/31 test box
NOTE: The ignition coil and power output stage are combined in one complete component.
Test requirement:
- Fuses for engine electronics OK
Procedure
- 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 from 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.
Check Ground (GND) connection
- Remove cover -1- in engine compartment (left side).
- Remove coolant reservoir (arrow)
- Disconnect electrical wiring to Engine Coolant Level (ECL) Warning Switch -F66- at bottom of reservoir.
- Lay aside coolant reservoir with connected coolant hoses -1- to -3-.
- Remove cover -1- in engine compartment (right side).
- Remove bolts (arrows).
- Detach Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- -1- at air guide.
- Remove air guide -2-.
- Remove air filter housing (arrows).
- Disconnect harness connector -1- at Mass Air Flow (MAF) sensor.
- Remove air guide hose -2- together with Mass Air Flow (MAF) sensor.
- Remove bolts (arrows) on cylinder head at right.
- Disconnect 4-pin harness connectors -1- to -3- at ignition coils.
- Remove bolts (arrows) on cylinder head at left.
- Disconnect 4-pin harness connectors -4- to -6- at ignition coils.
- 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 Ohm
- 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 2, terminal 8 to harness connector at ignition coil terminal 1.
- Check Motronic Engine Control Module (ECM) power supply relay -J271-. Testing and Inspection
Checking activation of power output stages
- Harness connector at ignition coils disconnected
- Remove all harness connectors to 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. Text Box, Connecting For Wiring Test
- Check the following wire connections for open circuit according to wiring diagram:
Harness connector Test box
Terminal Socket
3 (Cyl. 1) 102
3 (Cyl. 2) 110
3 (Cyl. 3) 94
3 (Cyl. 4) 103
3 (Cyl. 5) 111
3 (Cyl. 6) 95
- Specified value: Wire resistance max 1.5 Ohm
- Also check wires for short circuit to each other as well as to B+ and Ground (GND).
- Specified value: infinity Ohm (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". Diagnostic Mode 3: Check DTC Memory
2 - If necessary, erase DTC memory, "Mode 4: Reset/erase diagnostic data". Diagnostic Mode 4: Check Reset/Erase Diagnostic Data
3 - Generate readiness code. Readiness Code, Generating
- End diagnosis and switch ignition off.