Visual Inspection
IG "OFF"
Disconnect HO2S(B1/S2) connector.
Check that HO2S(B1S2) is contaminated or damaged by foreign materials.
Has a problem been found ?
YES
Go to "Check ECM" as follows.
NO
Substitute with a known - good HO2S(B1/S2) and check for proper operation.
If the problem is corrected, replace HO2S(B1/S2) and go to "Verification of Vehicle Repair" procedure.
Check ECM
IG "OFF".
Connect scantool and Engine "ON".
Select simulation function on scantool.
Simulate voltage at terminal 1 of HO2S(B1/S2) signal connector.
Does the signal value of HO2S(B1/S2) change according to simulation voltage ?
YES
Thoroughly check connectors for looseness, poor connection, bending, corrosion,contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Substitute with a known - good ECM and check for proper operation.
If the problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
