Checking wiring and components

Check signal cable (+) between control module #A42 and heated oxygen sensor (HO2S) connector terminal #4 for a short-circuit to supply voltage according to Short-circuit to supply voltage. Permanent faults , and a short-circuit to ground according to Short-circuit to ground, permanent faults .

Check signal cable (-) between control module #A41 and heated oxygen sensor (HO2S) connector terminal 3 for a short-circuit to supply voltage according to Short-circuit to supply voltage. Permanent faults , and a short-circuit to ground according to Short-circuit to ground, permanent faults .

If wiring is OK, try another heated oxygen sensor (HO2S).

Remedy as necessary.

Other information

To connect the breakout box, see Connecting the breakout box
To access/replace the heated oxygen sensor (HO2S), see Heated oxygen sensor (HO2S), replacing
For information about signals, see Signal specification

Fig 1: Identifying Heated Oxygen Sensor Terminal Connectors

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Ohmmeter

Courtesy of VOLVO CARS OF NORTH AMERICA.