FixVault

DTC Confirmation Test (Using Generic Scan Tool)

NOTE: Use the following test to check overall function of HO2S2 circuit. During this test, 1st trip DTC may not be confirmed.
CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  1. Start engine and warm it up to the normal operating temperature. Turn ignition switch OFF and wait at least 10 seconds. Start engine and keep the engine speed between 3500-4000 RPM for at least 1 minute. Let idle for 1 minute.
  2. Measure voltage between ground and ECM terminal No. 88 (bank 1) or No. 90 (bank 2) by backprobing. See Figure and Figure .
  3. While observing voltmeter, snap throttle to 4000 RPM at least 10 times. Voltage should be less than 0.48 volt at least once during this procedure.
  4. If voltage is as specified, system is okay at this time. If voltage is not as specified, go to next step.
  5. Let engine idle for 10 minutes, then measure voltage again. Or, measure voltage while coasting from 50 MPH in 3rd gear. If voltage is as specified, system is okay at this time. If voltage is not as specified, go to DIAGNOSTIC PROCEDURE .