DTC Confirmation Test (Using Generic Scan Tool)

WARNING: This page is about a different car, the 2003 Infiniti Q45. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the following test to check overall function of front HO2S circuit. During this test, 1st trip DTC may not be confirmed.

CAUTION: DO NOT use ECM ground terminals when measuring voltage.

Start engine and warm to normal operating temperature. Measure voltage between ground and left front HO2S signal circuit (Red/Blue wire) at ECM terminal No. 114 (DTC P1143), or right front HO2S signal circuit (Blue/White wire) at ECM terminal No. 115 (DTC P1163) by backprobing. See Figure and Figure . While observing voltmeter, increase engine speed to 2000 RPM. The following conditions should exist:

Maximum voltage should be more than .6 volt at least once.
Minimum voltage should be more than .1 volt at least once.

If voltage is not as specified, go to DIAGNOSTIC PROCEDURE . If voltage is as specified, system is okay at this time.