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Home >> Infiniti >> 2002 >> G20 Automatic, RE4F03W >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - G20 >> Diagnostic Tests >> DTC P1148: Closed Loop Control >> DTC Confirmation Test (Using Generic Scan Tool)
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DTC Confirmation Test (Using Generic Scan Tool)

NOTE: Use the following test to check closed-loop fuel control. During this test, DTC may not be confirmed.
CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  1. To check closed-loop operation, start engine and warm to normal operating temperature. Measure voltage between ground and ECM terminal 62 (front HO2S signal), by backprobing. See Figure and Figure .
  2. 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 DIAGNOSTIC PROCEDURE . If voltage is as specified, system is okay at this time.
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