Oxygen Sensor and Oxygen Sensor Control Before Catalytic Converter, Checking
Oxygen Sensor And Oxygen Sensor Control Before Catalytic Converter, Checking
NOTE:
- Vehicle must be raised before the oxygen sensor connector is accessible.
- When servicing terminals in harness connector of oxygen sensor, 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
Test requirements
- The respective fuses of Heated Oxygen Sensor (HO2S) -G39- 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 day time driving lights will be switched on.
- If vehicle is equipped with an A/C system, it must be switched off.
- For vehicles with automatic transmission, selector lever must be in -P-.
- 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 before catalytic converter must be OK, check. Oxygen Sensor Heater For Oxygen Sensor Before Three Way Catalytic Converter (TWC), Checking
Function test
- Select the following output of oxygen sensor signals and check whether the specified values are being reached. Diagnostic mode 5: Check output of oxygen sensor signals. Diagnostic Mode 5: Check Output of Oxygen Sensor Signals
- End diagnosis and switch ignition off.
If specified values are not obtained:
- Check oxygen sensor wires to control module according to wiring diagram.
Checking oxygen sensor wires to control module
- Remove protective cover (arrows) and disconnect 6-pin harness connector to Heated Oxygen Sensor (HO2S) -G39- before catalytic converter.
- Connect test box to control module wiring harness. connect test box for wiring test. Test Box, Connecting For Wiring Test
Vehicles with engine code APH, AWP, AWV
- Check wires between test box and 6-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram.
Terminal 1 + socket 70
Terminal 2 + socket 71
Terminal 5 + socket 51
Terminal 6 + socket 52
Wire resistance: max. 1.5 Ohms
Vehicles with engine code BKF, BNU
- Check wires between test box and 6-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram.
Terminal 1 + socket 52
Terminal 2 + socket 51
Terminal 5 + socket 71
Terminal 6 + socket 70
Wire resistance: max. 1.5 Ohms
Continue for all vehicles
- Check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite Ohms
- 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
If no malfunctions are found in wires:
- Replace Heated Oxygen Sensor (HO2S) -G39- bank 1 before catalytic converter.
- 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