Ignition/glow Plug System, Generic Scan Tool (3.0l Avk) Audi A4 B6

General notes on ignition system

1. The battery must only be disconnected and connected with the ignition switched off since the Engine Control Module (ECM) can otherwise be damaged.
2. For the electrical components to work properly, a voltage of at least 12.7 V is required.
3. 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.
4. 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 injection and 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-30l-avk) .
5. Always switch ignition off before cleaning engine.

Technical data, ignition

Ignition Technical Data Chart

Recommended special tools and equipment

1. VAG1526A 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.

Procedure

1. Start engine and let run at idle. Recognize a non-functional or misfiring cylinder as follows
2. Disconnect connectors from fuel injectors in sequence with engine running and observe engine operation. or
3. Compare spark plugs from all cylinders to each other. Check electrodes for carbon fouling. If faulty cylinder is recognized
4. Switch spark plug from faulty cylinder with one from another cylinder. If malfunction follows the spark plug
5. Replace spark plug. If malfunction remains at original cylinder
6. Switch ignition coil from faulty cylinder with one from another cylinder. If malfunction follows the ignition coil
7. Replace ignition coil.

Scheme 82

Scheme 83

1. Remove cover -1- in engine compartment (left side).
2. Remove coolant reservoir (arrow)
3. Disconnect electrical wiring to Engine Coolant Level (ECL) Warning Switch -F66- at bottom of reservoir.
4. Lay aside coolant reservoir with connected coolant hoses -1- to -3-.
5. Remove cover -1- in engine compartment (right side).
6. Remove bolts (arrows).
7. Detach Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- -1- at air guide.
8. Remove air guide -2-.
9. Remove air filter housing (arrows).
10. Disconnect harness connector -1- at Mass Air Flow (MAF) sensor.
11. Remove air guide hose -2- together with Mass Air Flow (MAF) sensor.
12. Remove bolts (arrows) on cylinder head at right.
13. Disconnect 4-pin harness connectors -1- to -3- at ignition coils.
14. Remove bolts (arrows) on cylinder head at left.
15. Disconnect 4-pin harness connectors -4- to -6- at ignition coils.
16. Connect e.g. V.A.G 1527 B voltage tester as follows: IGNITION COIL HARNESS CONNECTOR TERMINAL 2 & 4 CHART Harness connector Terminal Measure to 2 B+ 4 B+ LED must light up. If LED does notes lights up
17. Check the wire connections for open circuit. Specified value: Wire resistance max 1.5 ohm
18. If necessary, repair wire connection. If LED lights up

Scheme 84

1. Connect multimeter for voltage measurement as follows: IGNITION COIL HARNESS CONNECTOR TERMINAL 1 CHART Harness connector Terminal Measure to 1 Engine Ground (GND)
2. Switch ignition on. Specified value: approx. battery voltage
3. Switch ignition off. If specified value is obtained
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-30l-avk__checking-activation-of-power-output-stages) . If specified value is not obtained
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 2, terminal 8 to harness connector at ignition coil terminal 1.
2. Check Motronic Engine Control Module (ECM) power 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-30l-avk) .

Checking activation of power output stages

1. Harness connector at ignition coils disconnected

Scheme 85

1. 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.
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
5. 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-30l-avk) ; ECM is not connected.
6. Check the following wire connections for open circuit according to wiring diagram: IGNITION COIL HARNESS CONNECTOR TERMINAL 3 CHART Harness connector Terminal Test box 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
7. Also check wires for short circuit to each other as well as to B+ and Ground (GND). Specified value: INFINITY ohm (no continuity)
8. If necessary, repair wire connection. If no malfunctions are found in wires
9. 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-30l-avk__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-30l-avk__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-30l-avk) . End diagnosis and switch ignition off.

Check knock sensors

Recommended special tools and equipment

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

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.

1. Ignition switched off.

Scheme 86

1. Disconnect electrical 3-pin harness connector -2- for Knock Sensor (KS) 1 -G61-.
2. Disconnect electrical 3-pin harness connector -3- for Knock Sensor (KS) 2 -G66-. NOTE: To reach the harness connectors, the left cover in engine compartment must be removed, the line to Engine Coolant Level (ECL) Warning Switch at bottom on reservoir must be disconnected, and the bolt -arrow- of the coolant reservoir must be unscrewed and set aside. Coolant hoses -1- to -3- remain connected.
3. 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
4. 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-30l-avk) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram: Knock Sensor (KS) 1 -G61- (bank 1) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (KNOCK SENSOR 1, BANK 1) Harness connector Terminal Test box Socket 1 (signal) 106 2 (Ground -GND-) 99 3 (shielding) 108 Knock Sensor (KS) 2 -G66- (bank 2) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (KNOCK SENSOR 2, BANK 2) Harness connector Terminal Test box Socket 1 (signal) 107 2 (Ground -GND-) 99 3 (shielding) 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-30l-avk__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-30l-avk__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-30l-avk) . End diagnosis and switch ignition off.

Check Camshaft Position (CMP) sensor

Recommended special tools and equipment

1. VAG1526A 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 .

Note. To reach the harness connectors at cylinder bank 2 (left), the left cover in engine compartment must be removed, the line to Engine Coolant Level (ECL) Warning Switch at bottom on reservoir must be disconnected, and the bolt -arrow- of the coolant reservoir must be unscrewed and set aside. Coolant hoses -1- to -3- remain connected.

Scheme 87

1. Ignition switched off.

Checking activation

1. Connect voltage tester e.g. V.A.G 1527 B with measuring probes and connector adapters from V.A.G 1594 A between terminal 2 (CMP sensor signal) and terminal 1 (B+); the harness connector remains connected. NOTE: Connector socket numbers are shown on the rear side of the connector.
2. 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.
3. Switch ignition off. If LED does not blink

Scheme 88

1. Disconnect electrical harness connectors -1- and -2- at Camshaft Position (CMP) Sensor -G40- and Camshaft Position (CMP) Sensor 3 -G300-.
2. Disconnect electrical harness connectors -1- and -2- at Camshaft Position (CMP) Sensor 2 -G163- and Camshaft Position (CMP) Sensor 4 -G301-.
3. Connect multimeter for voltage measurement as follows: CMP SENSOR HARNESS CONNECTOR TERMINAL 1 Harness connector Terminal Measure to 1 Engine Ground (GND)
4. Switch ignition on. Specified value: about 5 V
5. Switch ignition off.

Scheme 89

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

Scheme 90

1. Connect multimeter for voltage measurement as follows: CMP SENSOR HARNESS CONNECTOR TERMINAL 3 Harness connector Terminal Measure to 3 B+ Specified value: about 10 V If all specified values are being reached and the LED does not blink (measured between terminal 1 and 2 with starter and connector connected)
2. Replace Camshaft Position (CMP) sensor. If specified values are not obtained

Checking wire connections between Camshaft Position (CMP) sensor and 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-30l-avk) ; ECM is not connected.
2. Check the following wire connections for open circuit according to wiring diagram

Scheme 91

Scheme 92

1. Camshaft Position (CMP) Sensor -G40- (bank 1) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (CAMSHAFT POSITION SENSOR 1, BANK 1) Harness connector Terminal Test box Socket 1 (B+) 98 2 (signal) 87 3 (Ground -GND-) 108
2. Camshaft Position (CMP) Sensor 2 -G163- (bank 2) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (CAMSHAFT POSITION SENSOR 2, BANK 2) Harness connector Terminal Test box Socket 1 (B+) 98 2 (signal) 86 3 (Ground -GND-) 108
3. Camshaft Position (CMP) Sensor 3 -G300- (bank 1) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (CAMSHAFT POSITION SENSOR 3, BANK 1) Harness connector Terminal Test box Socket 1 (B+) 98 2 (signal) 81 3 (Ground -GND-) 108
4. Camshaft Position (CMP) Sensor 4 -G301- (bank 2) HARNESS CONNECTOR TERMINAL 1, 2 & 3 (CAMSHAFT POSITION SENSOR 4, BANK 2) Harness connector Terminal Test box Socket 1 (B+) 98 2 (signal) 54 3 (Ground -GND-) 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-30l-avk__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-30l-avk__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-30l-avk) . 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