1990 Suzuki Swift GTFACTORY OEM SERVICE PROCEDURE

Idle Speed Control (ISC) System (Swift SOHC)

  1. Warm engine to normal operating temperature. See if Code 12 is present in self-diagnostics. See TESTS W/CODES article. If Code 12 is present, proceed to step 2). If Code 12 was not present, see appropriate INITIAL DIAGNOSTIC PROCEDURE in TESTS W/CODES article.
  2. Turn ignition switch on. Using stethoscope, check for operating sound at ISC solenoid. The ISC solenoid is mounted near air cleaner. If operating sound was heard, go to step 4). If no operating sound was heard, check ISC solenoid. See IDLE SPEED CONTROL (ISC) SOLENOID under IDLE CONTROL SYSTEM  in this article. Replace ISC solenoid if defective. If ISC solenoid was okay, go to step 3).
  3. Check for open or short in Red/White wire between ECM and ISC solenoid. Check for defective connection at ISC solenoid and ECM. If wiring and connections are okay, substitute ECM and recheck.
  4. With engine idling, disconnect ISC solenoid hose from air cleaner. Note if air is being drawn into the hose. If no air is being drawn in, check for clogged air passages. If air is being drawn in, system is operating correctly.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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