LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1991 >> Tercel LE, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Idle Control Systems >> Idle-Up System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Idle-Up System

  1. Inspect coolant temperature sensor for correct operation. See ENGINE SENSORS & SWITCHES . For idle-up vacuum switching valve location see Figure. Using ohmmeter, measure resistance between idle-up vacuum switching valve connector terminals. See Fig 1. Resistance should be 37-44 ohms. Ensure no continuity exists between vacuum switching valve case (body) and each terminal. If not as specified, replace vacuum switching valve.
  2. Ensure air DOES NOT flow between pipe "E" and pipe "F". If okay, apply battery voltage across vacuum switching valve terminals. See Fig 1. Air should now flow between pipe "E" and pipe "F". If air does not flow as indicated, replace vacuum switching valve.
Fig 1: Testing Idle-Up Vacuum Switching Valve
G91H16557Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002