DTC Confirmation Test (Overall Function Test)

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

NOTE: If DTC confirmation test has been previously performed, always turn ignition off and wait at least 10 seconds before performing next DTC confirmation test.

NOTE: Before proceeding, ensure ambient temperature is more than 14°F (-10°C) and battery voltage is more than 11 volts at idle.

CAUTION: To avoid damage to ECM, do not use ECM ground terminals when measuring voltage.

Start engine and warm to normal operating temperature. Measure voltage between ground and ECM terminal No. 92 (White/Green wire) 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 0.6 volt at least once.
- Minimum voltage should be more than 0.1 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.