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Closed Throttle (Idle) Switch

NOTE: It is important that all testing be done with Idle Speed Actuator (ISA) motor plunger in the fully extended position (as it would be after a normal engine shut down). See IDLE SPEED ACTUATOR (ISA) MOTOR in this article.
  1. Turn ignition switch to the "ON" position. Using a voltmeter, test closed throttle switch voltage at diagnostic connectors "D2" pin No. 13 and "D2" pin No. 7 (ground). See Fig 2 .
  2. On all models (except Wrangler) "D2" diagnostic connector is located on right fender well, behind relay block. On Wrangler model, "D2" connector is located on bracket, fender side of battery.
  3. Voltage should be close to zero at closed throttle and greater than 2 volts at any position other than closed throttle.
  4. If voltage is not present in either test, check for short to ground in wire harness or switch. If voltage is always greater than 2 volts, test for an open in wire harness between ECU and closed throttle switch connector and ground. Repair or replace wire harness as required.
Fig 1: Wide Open Throttle Switch
G120920Courtesy of CHRYSLER MOTORS.
Fig 2: Diagnostic Connectors "D1" & "D2" Terminal Identification
G120921Courtesy of CHRYSLER MOTORS.