CM850 Electronic Control System – 019-054   Idle Validation Switch

WARNING  Do not use DSES lubricant on throttle connectors.

The idle validation switch is located on the throttle assembly and is activated by moving the throttle to or from the idle position. The idle validation switch circuit consists of the Idle Validation Idle Switch Input, the Idle Validation Off Idle Switch Input, the Idle Validation Return and the Idle Validation Switch.

If INSITE™ electronic service tool is available, monitor the switch for proper operation. If not, follow the troubleshooting procedures in this section.

Locate the throttle assembly and disconnect the Idle Validation Switch connector from the Idle Validation Switch.

Adjust the multimeter to measure resistance.

Touch the multimeter probes to the idle validation idle switch input pin and idle validation return pin of the idle validation switch connector.

Move the throttle out of the idle position and measure the resistance. The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, the switch has failed. Replace the switch.

Touch the multimeter probes to the idle validation off idle switch input pin and the idle validation return pin of the idle validation switch connector.

Move the throttle to the idle position and measure the resistance. The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, the switch has failed. Replace the switch.

Touch the multimeter probes to the idle validation idle switch input line and the idle validation return line of the idle validation switch.

Move the throttle into the idle position and measure the resistance. The multimeter must show an closed circuit (10 ohms or less).

If the circuit is not closed, the switch has failed. Replace the switch.

Touch the multimeter probes to the idle validation off idle switch input line and the idle validation return line of the idle validation switch.

Move the throttle out of the idle position and measure the resistance. The multimeter must show an closed circuit (10 ohms or less).

If the circuit is not closed, the switch has failed. Replace the switch.

Check for a short circuit from pin to pin.

Touch the multimeter probe to the idle validation idle switch input line. Touch the other multimeter probe to the idle validation off idle switch input line.

Move the throttle into the idle position and measure the resistance. The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, there is a short circuit between the idle validation idle switch input and idle validation off idle switch input lines. Replace the switch.