LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Eagle >> 1989 >> Premier ES >> Repair and Diagnosis >> Engine Performance >> System >> 2.5L Systems/Tests W/Codes >> Diagnostic Trouble Code (DTC) Identification >> Relay Terminal Identification >> Closed Throttle Switch
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Closed Throttle Switch

  1. Ensure all testing is done with ISA/ISC plunger fully extended (as it would be after engine shutdown). If it is necessary to extend ISA/ISC plunger with a test switch, an ISA/ISC motor failure can be suspected.
  2. Turn ignition on. Connect a voltmeter between terminals "A" and "B" of ISA/ISC motor. Voltmeter reading should be close to zero at closed throttle and greater than 2 volts with throttle partially open.
  3. If voltage is not present in either position, check for a short circuit to ground in wiring harness or switch and check for an open circuit between ECU connector terminal "D5" and closed throttle switch.
  4. If voltage is always more than 2 volts, check for an open circuit between ECU and switch connector (ISA/ISC connector) and between switch connector and ground. Repair or replace as necessary.
scientia non olet · About LEMON Manuals