FixVault

Before Warm-Up

  1. Monitor vehicle's tachometer while cranking engine (at least 250 RPM).
  2. Ensure battery is fully charged and maintains at least 9.6 volts while cranking.
  3. Check fast idle cam.
  4. Check idle speed control circuit. See IDLE CONTROL SYSTEM in SYSTEM/COMP TESTS article.
  5. For Crank Signal & Idle Switch: Enter self-diagnostic Mode IV & perform appropriate switch tests.
  6. For Coolant Temperature Sensor: Enter self-diagnostic Mode III & retrieve codes. If vehicle will not start, crank engine before entering self-diagnostic Mode III.