LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Isuzu >> 1990 >> Impulse Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests - EFI >> Idle Control System >> Idle Air Control Valve (Impulse)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Idle Air Control Valve (Impulse)

  1. If Idle Air Control (IAC) valve is operating improperly, remove IAC valve from throttle body. Inspect IAC valve and throttle body bore for signs of binding or clogged passages. Repair as necessary. If binding or clogged passages was not present, proceed to step 2).
  2. Disconnect electrical connector from IAC valve. Using ohmmeter, check resistance across terminals No. 1 and No. 2 and across terminals. No. 3 and No. 4. See Fig 1 . Replace IAC valve if resistance is not 40-80 ohms.
  3. Using ohmmeter, check continuity across terminals No. 1 and No. 4 and across terminals. No. 2 and No. 3. See Fig 1 . Replace IAC valve if continuity exists.
  4. If IAC valve tested okay, check for faulty connections at IAC valve and ECM. If connections are okay, check input devices used by ECM to control IAC valve operation.
Fig 1: Identifying IAC Valve Terminals (Impulse)
G90I17994Courtesy of ISUZU MOTOR CO.
scientia non olet · About LEMON Manuals