DTC Confirmation Test (Overall Function Check)

Malfunction is detected when Engine Control Module (ECM) does not operate in closed loop.

Start engine and warm to normal operating temperature. Measure voltage between ground and ECM harness connector terminal No. 50 by backprobing. See Figure. Monitor voltmeter with engine at 2000 RPM. Voltage should be less than .21 volt at least once and more than .70 volt at least once. If voltage is not as specified, go to TEST PROCEDURE . If voltage is as specified, problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.