Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Closed Throttle Switch

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OPERATION



Eagle Throttle Body Fuel Injection (TBI) System

The Eagle TBI system is used only on the 2.5L Premier engine.

The closed throttle switch is an integral part of the idle speed actuator (ISC) motor and provides an input voltage to the PCM. This input enables the PCM to increase or decrease the throttle stop angle (by extending or retracting the ISC) in response to the operating conditions.

TESTING



Eagle Throttle Body Fuel Injection (TBI) System

It is important that all testing be done with the Idle Speed Control (ISC) actuator motor plunger in the fully extended position, as it would be after normal engine shutdown. If it is necessary to extend the ISC motor plunger to test the switch, an ISC motor failure can be suspected.

  1. With the ignition switch ON , test the switch voltage at the diagnostic connector terminals D213 (+) and D27 . The voltage should be close to zero at closed throttle and greater than 2 volts when off the closed throttle position.
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  3. If the voltage is always zero, test for a short circuit to ground in the wire harness or switch, or for an open circuit between PCM connector terminal 25 and the switch.
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  5. If the voltage is always more than 2 volts, test for an open circuit in the wire harness between the PCM and the switch connector, and between the switch connector and ground. Repair or replace the wire harness as necessary.
  6.  

REMOVAL & INSTALLATION



Eagle Throttle Body Fuel Injection (TBI) System

The closed throttle switch is an integral part of the Idle Speed Control (ISC) motor; for removal and installation of the ISC motor, refer to the ISC motor procedure later in this section.

 
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