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Home >> GMC >> 1998 >> Forward Control 7.4 J >> Repair and Diagnosis >> External Pages >> Different car >> Section 167 (Engine Controls - System & Component Testing) >> Idle Control System >> Idle Air Control System Diagnosis >> Test Description
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Test Description

WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to step numbers in diagnostic procedure.

  1. - This test will determine ability of PCM and IAC valve circuits to control IAC valve.
  2. - This test will determine ability of PCM to provide IAC valve circuits with ground. On a normally operating system, test light should not flash while IAC counts are incrementing.