Oxygen Sensor and Sensor Regulation Behind Catalyst, Checking
Oxygen sensor and oxygen sensor regulation behind catalytic converter, checking
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) -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 -P-.
- 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°C, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
- Oxygen sensor heater for oxygen sensor behind catalytic converter must be OK.
Test sequence
- Select lambda test results and check whether specified values are being reached, 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
- Disconnect 4-pin harness connector (brown) to Heated Oxygen Sensor (HO2S) 2 -G108-.
Vehicles > 08.99
- 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
Vehicles 09.99 >
- 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
Continue for all vehicles
- Switch ignition off.
If specified value is not obtained:
- Check oxygen sensor wires.
If specified value is obtained:
- Replace Heated Oxygen Sensor (HO2S) 2 -G108- bank 1:
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code.
Checking oxygen sensor wires
- Connect test box to control module wiring harness, connect test box for wiring test.
Vehicles >08.99
- Check wires between test box and 4-pin connector (to control module) for open circuit according to wiring diagram.
Terminal 3 + socket 58
Terminal 4 + socket 13
Wire resistance: max. 1.5 Ohms
- Check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite Ohms
Vehicles 09.99 >
- 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
- Check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite Ohms
Continued for all vehicles
If no malfunctions are found in wires:
- Replace Heated Oxygen Sensor (HO2S) 2 -G108- bank 1:
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code.