Heated Oxygen Sensor And Oxygen Sensor Control, Checking: Notes

NOTE:

Cylinder bank 1 is located in direction of travel, right.

Cylinder bank 2 is located in direction of travel, left.

Use only gold-plated terminals when servicing terminals in harness connector.

Special tools and workshop equipment required

Test Prerequisites

Fuses in E-box (plenum chamber, left) must be OK: Refer to SYSTEM WIRING DIAGRAM

Fig 1: Identifying Fuse Holder
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Power Supply Relay (Terminal 30, B+) Relay 2 -J689-, must be OK, check: Refer to SYSTEM WIRING DIAGRAM
Battery voltage must be at least 11.5 volts.
All electrical consumers such as, for example, lights and rear window defroster must be switched off.
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 01 - READ CURRENT SYSTEM DATA .
Oxygen sensor heater for oxygen sensors must be OK, check DIAGNOSTIC PROCEDURES .

Cylinder bank 1: Check Heated Oxygen Sensor (HO2S) -G39-, refer to HEATED OXYGEN SENSOR 2 (G39), TEST SEQUENCE .

Cylinder bank 2: Check Heated Oxygen Sensor (HO2S) 2 -G108-, refer to HEATED OXYGEN SENSOR 2 (G108) TEST SEQUENCE .