Oxygen Sensor and Oxygen Sensor Control Behind Catalytic Converter, Checking
Oxygen Sensor And Oxygen Sensor Control Behind Catalytic Converter, Checking
NOTE:
- Vehicle must be raised before connector for oxygen sensor is accessible.
- When servicing terminals 3 and 4 in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.
Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram
Requirements
- The respective fuses of Heated Oxygen Sensor (HO2S) -G130- must be OK.
- Battery voltage must be at least 11.5 Volts.
- All electrical consumers such as, lights and rear window defroster must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- For vehicles with automatic transmission, selector lever must be in position -P- or -N-.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Exhaust system must be properly sealed between catalytic converter and cylinder head.
- Coolant temperature must be at least 80 degrees C, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measured Values
- Oxygen sensor heater for oxygen sensor behind catalytic converter must be OK, check. Oxygen Sensor Heater For Oxygen Sensor Behind Three Way Catalytic Converter (TWC), Checking
Work sequence (Vehicles with engine code AEG, AVH, AZG, BEV)
- Select output of oxygen sensor signals and check whether specified values are being reached, Diagnostic mode 5: Check output of oxygen sensor signals. Diagnostic Mode 5: Check Output of Oxygen Sensor Signals
If specified values are obtained:
- End diagnosis and switch ignition off.
If specified values are not obtained:
- End diagnosis and let engine continue to run at idle.
- Check primary voltage.
Checking primary voltage
- Remove protective cover (arrows) and disconnect 4-pin harness connector (brown) -1- to Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC) -G130-.
- Connect multimeter for voltage measurement to terminals 3 + 4 of connector to Engine Control Module (ECM) and measure primary voltage.
Specified value: 0.400 to 0.500 Volts
- Switch ignition off.
If specified value is not obtained:
- Check oxygen sensor wires.
If specified value is obtained:
- Replace Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-:
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes.
Checking oxygen sensor wires
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
Vehicles with engine code AEG
- Check wires between test box and 4-pin connector (to control module) for open circuit according to wiring diagram.
Terminal 3 + socket 51
Terminal 4 + socket 52
Wire resistance: max. 1.5 Ohms
Vehicles with engine code AVH, AZG, BEV
- Check wires between test box and 4-pin connector (to control module) for open circuit according to wiring diagram.
Terminal 3 + socket 68
Terminal 4 + socket 69
Wire resistance: max.1.5 Ohms
Continued for all vehicles
- Check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite Ohms
If no malfunctions are found in wires:
- Replace Motronic Engine Control Module (ECM) -J220-.
Work sequence (vehicles with engine code BBW)
- Select output of oxygen sensor signals and check whether specified values are being reached, Diagnostic mode 5: Check output of oxygen sensor signals. Diagnostic Mode 5: Check Output of Oxygen Sensor Signals
If specified values are obtained:
- End diagnosis and switch ignition off.
If specified values are not obtained:
- End diagnosis and let engine continue to run at idle.
- Check primary voltage.
Checking primary voltage
- Remove protective cover -1- and disconnect 4-pin harness connector (brown) -5- to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-.
- Connect multimeter for voltage measurement to terminals 3 + 4 of connector to Engine Control Module (ECM) and measure primary voltage.
Specified value: 0.400 to 0.500 Volts
- Switch ignition off.
If specified value is not obtained:
- Check oxygen sensor wires.
If specified value is obtained:
- Replace Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- bank 1.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes.
Checking oxygen sensor wires
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
- Check wires between test box and 4-pin connector (to control module) for open circuit according to wiring diagram.
Terminal 3 + socket 68
Terminal 4 + socket 69
Wire resistance: max. 1.5 Ohms
- Check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite Ohms
If no malfunctions are found in wires:
- Replace Motronic Engine Control Module (ECM) -J220-.