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Idle Air Control Valve Mechanical Check

  1. Remove IAC valve from engine, leaving harness connector connected. Inspect rotary slide valve (arrow) for scoring. See Fig 1.
    2. CAUTION: When checking valve travel, DO NOT move rotary slide valve with screwdriver or other tool.
  2. Initiate Output Diagnostic Test Mode (DTM) until IAC valve is actuated. See OUTPUT DIAGNOSTIC TEST MODE (DTM) in SELF-DIAGNOSTICS article. Check whether rotary slide valve travels properly from stop to stop. See Fig 1.
  3. If scoring is severe enough to impair free movement or if the rotary slide valve: Binds, Runs slowly or Will not travel to both stops. Replace IAC valve.
Fig 1: Identifying Idle Air Control Valve's Rotary Slide Valve
G00177352Courtesy of AUDI OF AMERICA, INC.
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