Checking the connectors and components

WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.

Check the connectors for the front and rear heated oxygen sensor (HO2S). Check for contact resistance and oxidation.

NOTE:

Check that there is no oil or grease in the connectors.

Check the exhaust system for leakage. Check in particular between the front and rear heated oxygen sensor (HO2S) and between the exhaust manifold / turbocharger (TC) and the front heated oxygen sensor (HO2S).

Check the intake system for air leakage. Even extremely small air leaks can cause this diagnostic trouble code (DTC) to be stored.

Remedy as necessary.

HINT: The diagnostic trouble code (DTC) may also be due to a defective front or rear heated oxygen sensor (HO2S).

Try a new front heated oxygen sensor (HO2S) if no fault is found during the above fault-tracing.

Try a new rear heated oxygen sensor (HO2S) if the fault remains after the above fault-tracing.

Other information:

To check the exhaust system for leakage, see Checking the exhaust system for leakage
To check the intake system for leakage, see intake system/leak test
To connect the breakout box, see Connecting the breakout box. EMS 2000
For information about signals, see Signal specification
See Contents
To access or replace the front or rear heated oxygen sensor (HO2S), see Replace the front heated oxygen sensor (HO2S) .

Fig 1: Identifying Heated Oxygen Sensor (HO2S)

Courtesy of VOLVO CARS OF NORTH AMERICA.

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Refer to Verification