3.2L - Multiport Fuel Injection System, Servicing - Engine Code(s): Bub: Other Volkswagen Eos I

SAFETY PRECAUTIONS

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system. Note the following

1. Always switch off ignition before disconnecting or connecting lines of the fuel injection and ignition system, including test leads.
2. During some of the tests, a Diagnostic Trouble Code (DTC) may be recognized and stored by the control module. At the end of all tests and repairs, the DTC memory should be checked and, if necessary, erased. After erasing the DTC memory, a readiness code must be generated for the engine control module.
3. Always switch ignition off before cleaning engine.

Observe the following if test and measuring instruments are required during a test drive

CLEAN WORKING CONDITIONS

Even minor contaminations can lead to malfunctions in the fuel injection system. When working on the fuel supply/injection system, pay careful attention to the following rules for cleanliness

1. Thoroughly clean all unions and adjacent areas with engine or brake cleaner and dry before disconnecting.
2. Plug open lines and connections immediately with appropriate protective caps.
3. Place removed parts on a clean surface and cover. Use lint-free cloths.
4. Install clean components: Remove replacement parts immediately prior to installation. Do not use parts that have been stored unpacked (e.g. in tool boxes etc.).
5. When the system is open: Do not work with compressed air. Do not move vehicle unless absolutely necessary.
6. Separated electrical connectors: Protect from dirt and moisture. Make sure connections are dry when reconnecting.

TECHNICAL DATA

COMPONENTS, CHECKING

The following table provides quick links to all instructions in this section.

OXYGEN SENSOR HEATERS Z19 AND Z28, CHECKING

The following procedure is used to diagnose Oxygen Sensor (O2S) Heater -Z19- and Oxygen Sensor (O2S) 2 Heater -Z28-.

Note. When servicing electrical harness connector terminals for the Heated Oxygen Sensor (HO2S) --, use only gold-plated terminals.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Heated Oxygen Sensor (HO2S) -- Fuse 11 (on fuse panel B) -SB11- OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Checking internal resistance

Disconnect the Heated Oxygen Sensor (HO2S) -G39- electrical harness connector -2- or the Heated Oxygen Sensor (HO2S) 2 -G108- electrical harness connector -1-.

Scheme 104

Using a multimeter, check the Heated Oxygen Sensor (HO2S) -- terminals 3 to 4 for an open circuit.

Specified value: 2.5 to 10.0 ohms (at approx. 20° C)

If the specification was not obtained

Replace the 2- Heated Oxygen Sensor (HO2S) -G39- or the 1- Heated Oxygen Sensor (HO2S) 2 -G108-.

If the specification was obtained

Checking voltage supply

Using a multimeter, check the Heated Oxygen Sensor (HO2S) -- electrical harness connector terminal 4 to ground (GND) for voltage.

Scheme 105

Specified value: Battery voltage.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specification was obtained

Checking Ground (GND) activation

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a multimeter, check the Heated Oxygen Sensor (HO2S) -- electrical harness connector to the Engine Control Module (ECM) -J623- electrical harness connector T121 for an open circuit.

Specified value: 1.5 ohms max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

OXYGEN SENSOR HEATERS Z29 AND Z30, CHECKING

The following procedure is used to diagnose Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter (TWC)) Heater -Z29- and Oxygen Sensor (O2S) 2 (behind Three Way Catalytic Converter (TWC)) Heater -Z30-.

Note. Vehicle must be raised before electrical harness connector for the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- is accessible. When servicing terminals in harness connector of Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131-, use only gold-plated terminals.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- fuse OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Remove the right vehicle floor cover -arrows-.

Scheme 106

Checking internal resistance

Disconnect the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector -2- or the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- electrical harness connector -3-.

Scheme 107

Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -- terminals 1 to 2 for resistance.

Scheme 108

Specified value: 1.0 to 20.0 ohms (at approx. 20° C)

If the specification was not obtained

Replace the faulty Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) --.

If the specification was obtained

Checking voltage supply

Using a multimeter, check the Heated Oxygen Sensor (HO2S) -- electrical harness connector terminal 4 to ground (GND) for voltage.

Specified value: Battery voltage.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specification was obtained

Checking Ground (GND) activation

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -- electrical harness connector to the Engine Control Module (ECM) -J623- electrical harness connector T121 for an open circuit.

Scheme 109

Specified value: 1.5 ohms max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

MASS AIR FLOW SENSOR G70, CHECKING

Note. Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) Sensor -G70-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Mass Air Flow (MAF) Sensor -G70- / Intake Air Temperature (IAT) Sensor -G42- Fuse 10 (on fuse panel B) -SB10- OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Coolant Temperature at least 80° C.
8. Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Connect the scan tool.

Start engine and let it run at idle.

Using the scan tool, Check the air flow quantity of the Mass Air Flow (MAF) Sensor -G70- at idle

End diagnosis and switch ignition off.

If the specified value was obtained, but the DTC memory has a DTC concerning the Mass Air Flow (MAF) Sensor -G70

Check the voltage supply of the Mass Air Flow (MAF) Sensor -G70-.

If specified value was not obtained

Check the wiring of the Mass Air Flow (MAF) Sensor -G70-.

Checking voltage supply

Disconnect the Mass Air Flow (MAF) Sensor -G70- electrical harness connector -3-.

Scheme 110

Start the engine and let it run at idle.

Using a multimeter, check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminal 2 to engine Ground (GND).

Scheme 111

Specified value: battery voltage.

Switch the ignition off.

If specified value was not obtained

Check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminal 2 to the Motronic Engine Control Module (ECM) Power Supply Relay -J271- terminal 2/87 for an open circuit.

Specified value: 1.5 ohms max.

If no malfunction is detected in the wiring and if the voltage supply was OK

Checking electrical circuit

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a multimeter, check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminals for an open circuit.

Specified value: 1.5 ohms max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK

Replace Mass Air Flow (MAF) Sensor -G70-.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

THROTTLE VALVE CONTROL MODULE J338, CHECKING

Note. Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) Sensor -J338-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) -J623- fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Throttle valve must not be damaged or dirty.
8. Coolant Temperature at least 80° C.

Function

Throttle valve operation occurs via an electric motor (Throttle Drive (for Electronic Power Control (EPC)) -G186-) in Throttle Valve Control Module -J338-. It is operated by Engine Control Module (ECM) -J623- according to specifications of Throttle Position (TP) Sensor -G79- / Accelerator Pedal Position Sensor 2 -G185-.

Components of Throttle Valve Control Module -J338

1. Throttle Drive (for Electronic Power Control (EPC)) -G186
2. Throttle Drive Angle Sensor 1 (for Electronic Power Control (EPC)) -G187
3. Throttle Drive Angle Sensor 2 (for Electronic Power Control (EPC)) -G188

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Connect the scan tool.

Switch ignition on.

Using the scan tool, check the throttle valve position (absolute) at idle stop

Slowly depress the accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display. The percentage display must increase uniformly.

Using the scan tool, check the throttle valve position (absolute) at Wide Open Throttle (WOT) stop

End diagnosis and switch ignition off.

If the specified values are not obtained

Remove the Throttle Valve Control Module -J338- far enough so that the electrical connector terminals are reached.

Disconnect the Throttle Valve Control Module -J338- electrical harness connector -arrow-.

Scheme 112

Checking resistance

Using a multimeter, check the Throttle Drive (for Electronic Power Control (EPC)) -G186- at the Throttle Valve Control Module -J338- terminals 3 to 5 for resistance.

Scheme 113

Specified value: 1.0 to 5.0 ohms (at 20° C)

If the specification was not obtained

Replace the Throttle Valve Control Module -J338-.

If the specification was obtained

Check the voltage supply of the Throttle Valve Control Module -J338- to the Engine Control Module (ECM) -J623-, see "Checking voltage supply and wiring" (below)

Checking voltage supply and wiring

Switch the ignition on.

Using a Multimeter --, check the Throttle Drive (for Electronic Power Control (EPC)) -G186- at the Throttle Valve Control Module -J338- electrical harness connector terminals 2 to 6 for voltage.

Scheme 114

Specified value: at least 4.5 V

Switch the ignition off.

If the specification was not obtained

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter --, check the Throttle Drive (for Electronic Power Control (EPC)) -G186- at Throttle Valve Control Module -J338- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminals for an open circuit.

Scheme 115

Specified value: 1.5 ohms max.

If the specification is not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

If necessary, repair the faulty wiring connection.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If no malfunction is detected in the wiring and if the voltage supply was not OK

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

POSITIVE CRANKCASE VENTILATION HEATING ELEMENT N79, CHECKING

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connector of Positive Crankcase Ventilation (PCV) Heating Element -N79-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) -J623- fuses OK.
2. The Power Supply Relay (terminal 50) -J682- OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
6. A/C switched off.
7. Ground (GND) connections between engine/transmission/chassis OK.
8. Ignition switched off.
9. Engine cold.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Disconnect the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical harness connector -2-.

Scheme 116

Using a multimeter, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- terminals 1 to 2 for resistance.

Scheme 117

Specified value: 25 to 35 ohms (at approx. 20° C)

If the specified value was not obtained

Replace the Positive Crankcase Ventilation (PCV) Heating Element -N79-.

If the specified value was obtained

Checking voltage

Switch the ignition on.

Using a multimeter --, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 1 to Ground (GND) for voltage.

Scheme 118

Specified value: battery voltage.

Switch the ignition off.

If the specified value was not obtained

Check the wiring from the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 1 to the Power Supply Relay (terminal 50) -J682- socket 1/30 for a short circuit to Ground (GND), or an open circuit.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the wiring connection.

If no malfunctions are found in the wiring

Checking Ground (GND)

Using a multimeter --, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 2 to Ground (GND) for continuity.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring

Replace the Positive Crankcase Ventilation (PCV) Heating Element -N79-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

ENGINE COOLANT TEMPERATURE SENSOR G62, CHECKING

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connector of Engine Coolant Temperature (ECT) Sensor -G62-.

Special tools and workshop equipment required

1. Multimeter.
2. jumper wire.
3. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) - J623- fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.
8. Engine cold.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Connect the scan tool.

Switch the ignition on.

Using the scan tool, check the coolant temperature

If the specified value is not obtained

Continue test according to the following table

If the specified value was obtained

Start the engine and let it run at idle.

The temperature value must increase uniformly in increments of 1.0° C.

If the engine shows problems in certain temperature ranges and if the temperature does not climb uniformly, the temperature signal is intermittent.

Replace the the Engine Coolant Temperature (ECT) Sensor -G62-.

CHECKING INTERNAL RESISTANCE

Disconnect the Engine Coolant Temperature (ECT) Sensor -G62- electrical harness connector -arrow-.

Scheme 119

Using a multimeter, check the Engine Coolant Temperature (ECT) Sensor -G62- terminals 1 to 2 for resistance.

Use the chart below for the specified values

1. Area A: Resistance values 0 to 50° C.
2. Area B: Resistance values 50 to 100° C.

Specified values

Scheme 120

1. Range A, 30° C equals a resistance of 1.5 to 2.0 kohms
2. Range B, 80° C equals a resistance of 275 to 375ohms

If any of the specified values was not obtained

Replace the Engine Coolant Temperature (ECT) Sensor - G62-.

FINAL PROCEDURES

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis.

ENGINE COOLANT TEMPERATURE SENSOR G83 ON RADIATOR, CHECKING

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connector of Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) -J623- fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.
8. Engine cold.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Checking internal resistance

Disconnect the Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83- electrical harness connector -1-.

Using a multimeter, check the Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83- terminals 1 to 2 for resistance.

Use the chart below for the specified values

1. Area A: Resistance values 0 to 50° C.
2. Area B: Resistance values 50 to 100° C.

Specified values

1. Range A, 30° C equals a resistance of 1.5 to 2.0 kohms
2. Range B, 80° C equals a resistance of 275 to 375ohms

If any of the specified values was not obtained

Replace the Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83-.

If any of the specified values was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter --, check the Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminals for an open circuit according to the wiring diagram.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

COOLANT PUMP V51, CHECKING

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connector of Coolant Pump -V51-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Auxiliary Engine Coolant (EC) Pump Relay -J496- OK.
2. The Coolant Pump -V51- fuse OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
6. A/C switched off.
7. Ground (GND) connections between engine/transmission/chassis OK.
8. Ignition switched off.
9. Engine cold.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Disconnect the Coolant Pump -V51- electrical harness connector -arrow-.

Scheme 121

Checking voltage

Switch the ignition on.

Using a multimeter --, check the Coolant Pump -V51- electrical connector terminal 1 to Ground (GND) for voltage.

Specified value: battery voltage.

Switch the ignition off.

If the specified value was not obtained

Check the wiring from the Coolant Pump -V51- electrical connector terminal 1 to the Auxiliary Engine Coolant (EC) Pump Relay -J496- socket 2/87 for a short circuit to Ground (GND), or an open circuit.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the wiring connection.

If no malfunctions are found in the wiring

Checking Ground (GND)

Using a multimeter --, check the Coolant Pump -V51- electrical connector terminal 2 to Ground (GND) for resistance.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to, Battery (+), or an open.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Coolant Pump -V51-.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

ENGINE SPEED SENSOR G28, CHECKING

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connector of the Engine Speed (RPM) Sensor -G28-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) - J623- fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.

Function

The Engine Speed (RPM) Sensor -G28- detects RPM and reference marks. Without an engine speed signal, the engine will not start. If the engine speed signal fails while the engine is running, the engine will stop immediately.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Function test

Connect the scan tool.

Switch the ignition on.

Using the scan tool, check the engine speed

End diagnosis and switch ignition off.

If the specified value was not obtained

Checking internal resistance

Disconnect the gray Engine Speed (RPM) Sensor -G28- electrical harness connector -arrow-.

Scheme 122

Using a multimeter, check the Engine Speed (RPM) Sensor -G28- terminals 2 to 3 -B- for resistance.

Scheme 123

Specified value: 730 to 1000 ohms (at approx. 20° C)

Check Engine Speed (RPM) Sensor -G28- terminals 1 to 2 and 1 to 3 for short circuits.

Specified value: infinity (infinity)

If any of the specified values are not obtained

Replace the Engine Speed (RPM) Sensor -G28-.

If the specified values are obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter --, check the Engine Speed (RPM) Sensor -G28- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminals for an open circuit.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check wire shield for proper ground.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring

Remove the Engine Speed (RPM) Sensor -G28- and check the sensor wheel for proper seating, damage and run-out.

If the sensor wheel is OK

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

INTAKE MANIFOLD RUNNER CONTROL VALVE N316, CHECKING

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. Fuse -SB38- OK.
2. The Power Supply Relay (terminal 30, B+) -J317- OK.
3. The parking brake engaged.
4. The battery voltage at least 12.5 V.
5. The selector lever of automatic transmission in position "P" or "N".
6. All electrical consumers switched off (radiator fan must NOT run during test).
7. A/C switched off.
8. The fuel tank at least 1 / 4 filled.
9. The ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Disconnect the Intake Manifold Runner Control (IMRC) Valve -N316- electrical harness connector.

Checking internal resistance

Using a Multimeter --, check the Intake Manifold Runner Control (IMRC) Valve -N316- terminals 1 to 2 for resistance

Scheme 124

Specified value: 450 to 1000 ohms.

If the specified value was not obtained

Replace the Intake Manifold Runner Control (IMRC) Valve -N316-.

If the specified value was obtained

Checking voltage

Crank the engine.

Using a Multimeter --, check the Intake Manifold Runner Control (IMRC) Valve -N316- electrical harness connector terminal 1 to ground (GND) for voltage.

Scheme 125

Specified value: battery voltage.

Switch the ignition off.

If the specified value was not obtained

Check the wiring from the Intake Manifold Runner Control (IMRC) Valve -N316- electrical harness connector terminal 1 to the Power Supply Relay (terminal 30, B+) -J317- terminal 87 for a short circuit to Ground (GND), or an open circuit.

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the wiring connection.

If no malfunctions are found in the wiring

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Motronic Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a multimeter --, check the Intake Manifold Runner Control (IMRC) Valve -N316- electrical harness connector terminal 2 to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminal 121 for an open circuit.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

FUEL INJECTORS N30, N31, N32, AND N33, CHECKING

The following test procedure is used to diagnose Fuel Injectors -N30, N31, N32, N33, N83, N84-.

FUNCTIONS, CHECKING

The following table provides quick links to all instructions in this section.

HEATED OXYGEN SENSORS G39 AND G108, CHECKING

The following procedure is used to diagnose both Heated Oxygen Sensor (HO2S) -G39- and Heated Oxygen Sensor (HO2S) 2 -G108

Note. Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Heated Oxygen Sensor (HO2S) -G39- and Heated Oxygen Sensor (HO2S) 2 -G108-.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Heated Oxygen Sensor (HO2S) -G39- and Oxygen Sensor (O2S) 2 Heater -Z28- fuses OK.
2. The Oxygen Sensor (O2S) Heater -Z19- and Oxygen Sensor (O2S) 2 Heater -Z28- before catalytic converter OK. Refer to.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Exhaust system between catalytic converter and cylinder head properly sealed.
8. Coolant Temperature at least 80° C.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Function test

Connect scan tool.

Start the engine and let it run at idle.

Select "Diagnostic mode 6: Check test results of components that are not continuously monitored".

Select "Test-ID 01: Oxygen sensor monitoring before catalytic converter".

Select "Test-ID 131: Dynamic test".

Check the specified values at idle.

If specified values are obtained

End diagnosis and switch the ignition off.

If the specified values are not obtained

Checking primary voltage

Disconnect the black Heated Oxygen Sensor (HO2S) -G39- electrical harness connector -1- or the Heated Oxygen Sensor (HO2S) 2 -G108-.

Scheme 126

Using a multimeter, check the Heated Oxygen Sensor (HO2S) -- electrical harness connector -1- terminals 1 to 5 for voltage.

Specified value: 0.400 to 0.500 Volts

Switch the ignition off.

If the specified value was not obtained

Replace the Heated Oxygen Sensor (HO2S) -G39- or the Heated Oxygen Sensor (HO2S) 2 -G108-.

If the specified value was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter --, check the Heated Oxygen Sensor (HO2S) -G39- or the Heated Oxygen Sensor (HO2S) 2 -G108- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminals for an open circuit.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

OXYGEN SENSORS G130 AND G131, CHECKING

The following procedure is used to diagnose both Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131

Note. Vehicle must be raised before the electrical connector of the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- is accessible. When servicing terminals 3 and 4 in the electrical harness connector of the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131-, use only gold-plated terminals.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- fuses Ok.
2. Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter (TWC)) Heater -Z29- and Oxygen Sensor (O2S) 2 (behind Three Way Catalytic Converter (TWC)) Heater -Z30- OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. Vehicles with automatic transmission, selector lever in position "P" or "N".
6. A/C switched off.
7. Ground (GND) connections between engine/transmission/chassis OK.
8. Exhaust system between catalytic converter and cylinder head properly sealed.
9. Coolant Temperature at least 80° C.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Function test

Connect scan tool.

Start the engine and let it run at idle.

Select "Diagnostic mode 6: Check test results of components that are not continuously monitored".

Select "Test-ID 02: Oxygen sensor monitoring behind catalytic converter".

Select following Test-IDs.

Check the specified values at idle.

If the specified values are obtained

End diagnosis and switch ignition off.

If the specified values are not obtained

Remove the right vehicle floor cover -arrows-.

Checking primary voltage

Disconnect the brown Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector -1- or Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- -2-.

Scheme 127

Switch the ignition on.

Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector terminals 3 to 4 for voltage.

Specified value: 0.400 to 0.500 Volts

Switch the ignition off.

If the specified value was obtained

Replace the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- or Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131-.

If the specified value was not obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter --, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector terminals to the Engine Control Module (ECM) -J623- or Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- electrical harness connector T121 terminals for an open circuit.

Specified value: 1.5 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

ENGINE CONTROL MODULE

The following table provides quick links to all instructions in this section.

FUNCTION

Engine Control Module (ECM) -J623- regulates fuel injection, Throttle Valve Control Module -J338-, oxygen sensor regulation, ignition, knock control, Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-, engine speed limitation through fuel injectors or Fuel Pump (FP) Relay -J17- as well as On Board Diagnostic (OBD).

VOLTAGE SUPPLY, CHECKING

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Engine Control Module (ECM) -J623- fuses OK.
2. Battery voltage at least 12.5 volts.
3. All electrical consumers such as, lights and rear window defroster, switched off.
4. Vehicles with automatic transmission, selector lever in position "P" or "N".
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Remove the Engine Control Module (ECM) Power Supply Relay -J271-.

Checking voltage

Using a Multimeter, check the Engine Control Module (ECM) Power Supply Relay -J271- socket 4/85 to Ground (GND).

Specified value: battery voltage.

If the specified value was not obtained

Check the wiring connections from the Battery to the Engine Control Module (ECM) Power Supply Relay -J271- socket 3/86 for an open circuit or a short circuit.

Check the wiring connections for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If the specified value was obtained

Switch the ignition on.

Using a Multimeter, check the Engine Control Module (ECM) Power Supply Relay -J271- socket 4/85 to Ground (GND).

Specified value: battery voltage.

If the specified value was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter, check the Engine Control Module (ECM) Power Supply Relay -J271- socket 4/85 to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminal 65 for resistance.

Specified value: 2.0 ohms Max.

If the specification was not obtained

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

Check the electrical harness connector for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

Checking activation

Switch the ignition on.

Using a Multimeter, check the Engine Control Module (ECM) Power Supply Relay -J271- socket 4/85 to the Engine Control Module (ECM) -J623- electrical harness connector T121 terminal 65 for voltage.

Switch the ignition off.

Specified value: 0.5 V Max.

If the specified value was obtained

Replace the Engine Control Module (ECM) Power Supply Relay -J271-.

If the specified value was not obtained

Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

Check the wiring connection for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was OK

Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

Perform a road test to verify repair.

If the DTC does not return

Repair complete, Generate readiness code. Refer to READINESS CODE DESCRIPTION .

End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Assembly is performed in the reverse of the removal.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

ENGINE CONTROL MODULE J623, REPLACING

Removing

Special tools and workshop equipment required

1. Heat gun.

Note. When the Engine Control Module (ECM) -J623- electrical harness connectors are disconnected, the adaptation values are erased and the DTC memory content remains intact.

Work procedure

Check the identification of the previous Engine Control Module (ECM) -J623- as follows

Connect the scan tool.

Switch the ignition on.

Using the scan tool, select "Vehicle information".

Select "Calibration Identification" in vehicle information.

The electronic control module identification number will be displayed, e.g.: 06A906032NA 4983

Record the electronic control module identification number.

End diagnosis and switch the ignition off.

Procedure

Switch the ignition on.

Actuate the touch-wipe function to allow the wipers to move to the end position.

Note. The wiper arms will now move into the line of view on the windshield (service position).

Remove the wiper arms caps.

Loosen the wiper arm nuts -arrows- several turns.

Scheme 128

Loosen the wiper arms from the wiper axle by rocking slightly.

Remove windshield wiper arms, plenum chamber cover and plenum chamber facing wall Refer to WINDSHIELD WIPER SYSTEM .

Note. The threads of the shear bolts have been coated with a locking compound and must be heated to be removed.

The Engine Control Module (ECM) -J623- is secured via a protective housing -1- and shear bolts -2

Scheme 129

Using a Heat gun set at its lowest setting, heat the shear bolt for approx. 20 to 25 seconds.

Remove the shear bolt with locking pliers. Discard the used shear bolts.

Repeat the previous steps for the second shear bolt.

Remove the protective housing from the Engine Control Module (ECM) -J623-.

Remove the front electrical harness connector -1- from the Engine Control Module (ECM) -J623-.

Insert a screwdriver -A- between the protective housing and retaining plate -arrow-.

Scheme 130

Pry the protective housing upward using screwdriver -A- and pull it off sideways from retaining plate -arrow-.

Scheme 131

Disconnect the forward electrical harness connector -1- from Engine Control Module (ECM).

Pry up locking mechanism -2- slightly.

Slide the Engine Control Module (ECM) out of retainer -arrow-.

Scheme 132

Disconnect the rear harness connector from Engine Control Module (ECM).

Engine Control Module (ECM) -J623- installation

Installation is performed in reverse order of removal. Note the following

The Engine Control Module (ECM) -J623- must be installed with the protective housing.

Use New shear bolts when installing the Engine Control Module (ECM) -J623-.

Engine Control Module (ECM) -J623- reprogramming

The new Engine Control Module (ECM) -J623- and immobilizer must be activated.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

ADDITIONAL SIGNALS, CHECKING

The following table provides quick links to all instructions in this section.

SPEED SIGNAL, CHECKING

The following procedure requires a test drive. Observe all Safety Precautions.

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirements

1. The Speedometer -G21- OK.
2. The Engine Control Module (ECM) -J623- fuses OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. A/C switched off.
6. Ground (GND) connections between engine/transmission/chassis OK.
7. Ignition switched off.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

Connect the scan tool.

Function test

Perform a road test with a vehicle speed greater than 5 Km/h.

Using the scan tool, Check the vehicle speed

Compare the vehicle speed on the scan tool to the Speedometer -G21-.

Specified value: a difference of no greater than 10%.

If the specified value was not obtained or no speed was displayed

Check the wiring from the Engine Control Module (ECM) -J623- to the Instrument Cluster Control Module -J285- for an open circuit, Short to Battery (+), or to Ground (GND).

Check the wiring connection for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis

CAN-BUS TERMINAL RESISTANCE, CHECKING

Special tools and workshop equipment required

1. Multimeter.
2. Wiring diagram.

Test requirement

1. A CAN-Bus malfunction was recognized.
2. The Engine Control Module (ECM) -J623- fuses OK.
3. Battery voltage at least 12.5 volts.
4. All electrical consumers such as, lights and rear window defroster, switched off.
5. Vehicles with automatic transmission, shift selector lever into position "P" or "N".
6. A/C switched off.
7. Ground (GND) connections between engine/transmission/chassis OK.
8. Ignition switched off.

Function

The Engine Control Module (ECM) -- communicates with other CAN-Bus capable control modules.

The control modules are connected by two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the CAN-bus is recognized as a malfunction by the Engine Control Module (ECM) -- and the other control modules connected to the CAN-bus.

Trouble-free operation of the CAN-Bus requires that it have a terminal resistance. This central terminal resistance is located in the Engine Control Module (ECM) --.

If the CAN-Bus communication is interrupted. Communication from the scan tool to the Engine Control Module (ECM) -- may not be possible.

Test procedure

Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis

Disconnect the Data Bus On Board Diagnostic Interface -J533- electrical harness connector.

Note. The Engine Control Module (ECM) -J623- must remain connected for the following step.

Using a Multimeter, check the Data Bus On Board Diagnostic Interface -J533- electrical harness connector terminals 6 to 16 for resistance.

Specified value: 60 to 72 ohms (at approx. 20° C)

If the specified value was not obtained

Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

Check the wiring connection for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

Replace the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

If the specified value was obtained

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the Test Box 105 PinVAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

Remove the Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE J623, REPLACING .

Using a Multimeter, check the Data Bus On Board Diagnostic Interface -J533- electrical harness connector to the Engine Control Module (ECM) -J623- electrical harness connector T121 for resistance.

Specified value: 1.5 ohms Max.

If the specified value was not obtained

Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

Check the wiring connection for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring

Replace the Data Bus On Board Diagnostic Interface -J533-.

Final procedures

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

1. Check the DTC memory. Refer to «DIAGNOSTIC MODE 03 - READ DTC MEMORY»(ref-475605-S30658758892012052300000) .
2. If necessary, erase the DTC memory. Refer to «DIAGNOSTIC MODE 04 - ERASE DTC MEMORY»(ref-475605-S15898996512012052300000) .
3. If the DTC memory was erased, generate readiness code. Refer to «READINESS CODE»(ref-475605-S28850913172012052300000) .

End of diagnosis