Ignition/glow Plug System, Generic Scan Tool -1.8l 5v Turbo, Amb Audi A4 B6

General notes on ignition system

1. For the electric components to work properly, a voltage of at least 12.5 V is required.
2. It is possible that the control module will recognize a malfunction and store a DTC during some tests. After completing all tests and repairs, DTC memory should therefore be checked and erased if necessary.
3. If the engine only starts briefly and then turns off again after troubleshooting, repair or checking of the components, it may be that the immobilizer is blocking the Engine Control Module (ECM). DTC memory must then be checked and if necessary, control module must be adapted.

Safety precautions

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system, always observe the following

1. Do not touch or disconnect ignition wires when engine is running or turning at starting RPM.
2. Always switch ignition off before disconnecting or reconnecting wires for the ignition system, including high voltage wiring and test leads.
3. If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect connector from ignition coils and from fuel injectors.
4. It is possible that the control module will recognize a malfunction and store a DTC during some tests. After completing all tests and repairs, DTC memory should therefore be checked and erased if necessary. Readiness code must be generated after DTC memory is erased. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .
5. Always switch ignition off before cleaning engine.

Technical data, ignition

IGNITION TECHNICAL DATA

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. V.A.G 1527 B Voltage Tester
3. VAG1594A connector test kit
4. VAG1598/31 test box

Note. The ignition coil and power output stage are combined in one complete component.

Test requirement

1. Fuses for engine electronics OK See appropriate System Wiring Diagrams article.

Work procedure

1. Remove engine cover (arrows).
2. Start engine and let run at idle.
3. Disconnect connectors from fuel injectors in sequence with engine running and observe engine operation.
4. Compare spark plugs of all cylinders to each other. Check electrodes for carbon fouling.
5. Switch spark plug from faulty cylinder with one from another cylinder.
6. Replace spark plug.
7. Switch ignition coil from faulty cylinder with one from another cylinder.
8. Replace ignition coil.

Scheme 33

1. Disconnect the 4-pin harness connector -1- at the ignition coil -2-.
2. Connect e.g. V.A.G 1527 B voltage tester as follows: IGNITION COIL POWER OUTPUT STAGE: TERMINAL 2, 4 MEASURE Harness connector Terminal Measure to 2 B+ 4 B+ LED must light up.
3. Check the wire connections for open circuit. Specified value: Wire resistance max 1.5ohm
4. If necessary, repair wire connection.

If LED lights up

Scheme 34

1. Connect multimeter for voltage measurement as follows: IGNITION COIL POWER OUTPUT STAGE: TERMINAL 1 MEASURE Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Switch ignition on. Specified value: approx. battery voltage
3. Switch ignition off.
4. Check activation of power output stages. See «CHECKING ACTIVATION OF POWER OUTPUT STAGES»(/audi/a4/b6-2000-2006/remont/ignition-system/#ignitionglow-plug-system-generic-scan-tool-18l-5v-turbo-amb__checking-activation-of-power-output-stages) .
5. Remove rubber seal for plenum chamber cover.
6. Remove plenum chamber cover -1- toward front (arrows).
7. Pry off both covers -3- using a screwdriver.
8. Loosen hex-nuts -4- by several turns.
9. Loosen wiper arm -2- from wiper axle by lightly tilting.
10. Remove hex nuts completely and remove wiper arms.
11. Disconnect securing clips -1- and remove cowl grill -5-.
12. Remove cover for E-box, plenum chamber (arrows).
13. Pry off Engine Control Module (ECM) retaining bracket (arrows) using a screwdriver and set control module aside.
14. If installed, unclip Transmission Control Module (TCM) retaining bracket and set control module aside.
15. Disconnect voltage supply relay -2-.
16. Perform the following tests marked with dots

1. Check wire connection from relay carrier in E-box, plenum chamber, position 3, terminal 8 to harness connector at ignition coil terminal 1.
2. Check Motronic Engine Control Module (ECM) voltage supply relay -J271-. See «CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION»(/audi/a4/b6-2000-2006/remont/fuel-system/#multiport-fuel-injection-mfi-generic-scan-tool-18l-5v-turbo-amb__check-motronic-engine-control-module-ecm) .

Checking activation of power output stages

1. Harness connectors at ignition coils disconnected

1. 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.
2. Connect e.g. V.A.G 1527 B voltage tester to connector terminals 2 and 3.
3. Operate starter briefly. LED must blink (brief blink signal).
4. Switch ignition off.

If LED does not blink

Scheme 35

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: IGNITION COIL POWER OUTPUT STAGE: TERMINAL & SOCKETS OF POWER OUTPUT STAGES Harness connector Terminal VAG1598/31 test box Socket 3 (Cyl. 1) 102 3 (Cyl. 2) 95 3 (Cyl. 3) 103 3 (Cyl. 4) 94 Specified value: Wire resistance max 1.5 ohm
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
4. If necessary, repair wire connection.
5. 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. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Check knock sensors

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. VAG1594A connector test kit
3. VAG1598/31 test box

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Ignition switched off.

Checking knock sensor wiring

Note. Knock Sensor (KS) 1 -G61- and Knock Sensor (KS) 2 -G66- themselves cannot be electrically tested. When servicing terminals in harness connector of knock sensors, use only gold-plated terminals. For the Knock Sensors to function properly, it is important for tightening torque to be exactly 20 N.m. Check harness connector from knock sensor to wiring harness for corrosion.

Scheme 36

Scheme 37

Scheme 38

1. Disconnect harness connector for Knock Sensor (KS) 1 -G61- (item 1) or Knock Sensor (KS) 2 -G66- (item 4). NOTE: Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.
2. Check all three terminals at knock sensor connector for short circuit to each other (terminal 1+2, 1+3, 2+3). Specified value: INFINITY ohm (no continuity) - the wires must not have any connection to each other.
3. If there is a connection, replace knock sensor.

If no malfunction can be found

Check wires from knock sensors to Engine Control Module (ECM)

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram

1. Knock Sensor (KS) 1 -G61- (bank 1) KNOCK SENSOR 1 TERMINAL & SOCKETS Harness connector Terminal Test box Socket 1 (signal) 106 2 (Ground -GND-) 99 3 (shielding) 108
2. Knock Sensor (KS) 2 -G66- (bank 2) KNOCK SENSOR 2 TERMINAL & SOCKETS Harness connector Terminal Test box Socket 1 (signal) 107 2 (Ground -GND-) 99 3 (shielding) 108

1. Specified value: Wire resistance max 1.5 ohm

1. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
2. If necessary, repair wire connection.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. Erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) .

1. End diagnosis and switch ignition off.

Camshaft Position (CMP) Sensor -G40-, checking

Recommended special tools and equipment

1. VAG1526A hand multimeter
2. V.A.G 1527 B Voltage Tester
3. VAG1594A connector test kit
4. VAG1598/31 test box

Component location. See OVERVIEW OF COMPONENT LOCATIONS .

1. Ignition switched off.

Checking activation

1. If installed, slide back rubber grommet from connector for Camshaft Position (CMP) sensor.
2. Connect voltage tester e.g. V.A.G 1527 B with measuring probes and connector adapters from V.A.G 1594 A between socket 2 (CMP sensor signal) and socket 1 (B+); the harness connector remains connected. NOTE: Connector sockets are numbered respectively on the rear side of the connector.
3. Operate starter for a few seconds. LED must blink. NOTE: Voltage testers do not go out completely during low current pick-up between activations by the ECM, but rather continue to glow a little and then get significantly brighter during activation.
4. Switch ignition off.

If LED does not blink

Scheme 39

1. Disconnect harness connector (arrow) from Camshaft Position (CMP) Sensor -G40-.
2. Connect multimeter for voltage measurement as follows: CAMSHAFT POSITION (CMP) SENSOR: TERMINAL 1 MEASURE Harness connector Terminal Measure to 1 Engine Ground (GND)
3. Switch ignition on. Specified value: about 5 V
4. Switch ignition off.

Scheme 40

1. Connect multimeter for voltage measurement as follows: CAMSHAFT POSITION (CMP) SENSOR: TERMINAL 2 MEASURE Harness connector Terminal Measure to 2 Engine Ground (GND)
2. Switch ignition on. Specified value: approx. battery voltage
3. Switch ignition off.

Scheme 41

1. Connect multimeter for voltage measurement as follows: CAMSHAFT POSITION (CMP) SENSOR: TERMINAL 3 MEASURE Harness connector Terminal Measure to 3 B+ Specified value: about 10 V
2. Replace Camshaft Position (CMP) sensor.

If specified values are not obtained

Scheme 42

1. Connect test box to wiring harness of Engine Control Module (ECM). See «TEST BOX, CONNECTING FOR WIRING AND COMPONENT TEST»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: CAMSHAFT POSITION SENSOR CIRCUIT TEST: TERMINAL & SOCKETS Harness connector Terminal Test box Socket 1 (B+) 98 2 (signal) 86 3 (Ground -GND-) 108 Specified value: Wire resistance max 1.5 ohm
3. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
4. If necessary, repair wire connection.

After repair work, the following work steps must be performed in the mentioned sequence

1. Check DTC memory. See «MODE 3: CHECK DTC MEMORY»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-3-check-dtc-memory) .
2. If necessary, erase DTC memory. See «MODE 4: RESET/ERASE DIAGNOSTIC DATA»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb__mode-4-reseterase-diagnostic-data) .
3. Generate readiness code. See «READINESS CODE, GENERATING»(/audi/a4/b6-2000-2006/remont/testing-diagnostics/#engine-controls-on-board-diagnostic-obd-generic-scan-tool-18l-5v-turbo-amb) . End diagnosis and switch ignition off.

See also:
• BATTERY DISCONNECT PRECAUTIONS
• READINESS CODE, GENERATING
• CHECK MOTRONIC ENGINE CONTROL MODULE (ECM) POWER SUPPLY RELAY -J271- AND ACTIVATION
• MODE 3: CHECK DTC MEMORY
• MODE 4: RESET/ERASE DIAGNOSTIC DATA
• OVERVIEW OF COMPONENT LOCATIONS
• CHECKING ACTIVATION OF POWER OUTPUT STAGES