Electronic Idle Speed Control
- The idle speed control is independent of the airflow sensor position indicator. Run engine at operating temperature, with shift lever in position "P" or "N". Turn A/C compressor off.
- Ensure air intake system has no air leaks. Check that idle speed contact, coolant temperature sensor and EGR system are functioning properly. At altitudes above 2000 feet, the current draw can fall below 700 mA.
- Connect Test Cable (102 589 04 63 00) to idle speed air valve. Set multimeter to mA scale. Connect tachometer and start engine.
- With idle speed set at 675 RPM. Current draw should be 700-1000 mA, if not, perform idle speed stabilization check. See ENGINE IDLE SPEED STABILIZATION in this section. With idle at 675 RPM, current draw should be 70-700 mA. If not within specifications, enlarge air by-pass bore (420 engine only). See Fig 1 .
- If idle speed is too high, stop engine. Unplug idle speed control unit. Check wires between idle speed air valve and idle speed control unit for continuity. Resistance should about zero ohms. If not, repair circuit as necessary. If okay, go to step 6).
- Check resistance of idle speed air valve. Resistance should be 3.5-4.5 ohms. If not okay, replace idle speed air valve. If okay, turn on ignition. Check voltage between terminals No. 9 and 11 of idle speed control unit plug. Voltage should about 12 volts. If not okay, check power supply and ground connection. If okay, replace idle speed control unit.