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Test Ee - Idle Speed Control

To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault: anti-diesel (run-on) speed set too high, engine condition (valves, vacuum leaks, valve timing, EGR valve, etc.), vacuum leaks, sticking throttle or on high cam.

  1. Code 68 Displayed. Turn key off and wait 10 seconds. Move throttle away from Idle Speed Control (ISC) motor shaft to simulate no throttle contact. Perform KEY ON/ENGINE OFF (KOEO) SELF-TEST. Check for code 68. Ignore all other codes at this time. If code 68 is displayed, release throttle and go to step 3). If code 68 is not displayed, release throttle and go to next step.
  2. Turn key off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Install a jumper wire between test pins No. 41 and 1, and between test pin No. 21 and ground. If ISC motor does not retract, remove jumper wire and go to step 5). If ISC motor retracts and contacts throttle lever, check ISC mechanical adjustments. If ISC motor retracts, but does not contact throttle lever, remove jumper wire and go to step 24).
    NOTE: DO NOT  leave jumper wire in test pins if ISC motor will not move. Remove jumper wire as it will damage breakout box wiring.
  3. Turn key off and wait 10 seconds. Disconnect harness at ISC motor. Install a jumper wire between pins No. 3 and 4 at ISC connector to simulate closed contact condition. Perform KOEO SELF-TEST. If code 68 is not displayed, replace motor and repeat QUICK TEST  . If code 68 is displayed, go to next step.
    Fig 1: ISC Motor Jumper Wire Installation
    G6053
  4. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Leave ISC harness disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between test pin No. 46 and signal return circuit at ISC connector. Also measure resistance between test pin No. 28 (24 on Sable/Taurus) and Idle Tracking Switch (ITS) circuit at ISC connector. If either reading is 5 ohms or more, repair bad circuit. Repeat QUICK TEST  . If both readings are less than 5 ohms, replace ECA. Repeat QUICK TEST  .
  5. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Disconnect ISC motor harness and set DVOM on 200-ohm scale. Measure resistance between test pin No. 41 and ISC ground circuit, and between test pin No. 21 and ISC power circuit at ISC connector. If either reading is 5 ohms or more, repair wiring and repeat QUICK TEST  . If both readings are less than 5 ohms, go to next step.
  6. Turn key on, leaving engine off. Leave breakout box installed and ECA disconnected. Leave harness disconnected from ISC motor and set DVOM on 20-volt scale. Measure voltage between test pin No. 41 and test pins No. 40 and 60. Also measure voltage between test pin No. 21 and test pins No. 40 and 60. If any reading is one volt or more, repair short to power. Repeat QUICK TEST  . If code 12 is still displayed, replace ECA and repeat QUICK TEST  . If all readings are less than one volt, go to next step.
  7. Turn key off and wait 10 seconds. Leave breakout box installed with ECA and ISC motor disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between test pin No. 41 and test pins No. 40, 46 and 60. Also measure resistance between test pin No. 21 and test pins No. 40, 46, and 60. If any reading is 10,000 ohms or less, repair bad circuit. Repeat QUICK TEST  . If code 12 is still displayed, replace ECA and repeat QUICK TEST  . If all readings are more than 10,000 ohms, go to next step.
  8. Turn key off and wait 10 seconds. Leave breakout box installed with ECA and ISC motor disconnected. Set DVOM on 20-volt scale. Connect DVOM positive test lead to test pin No. 1 and negative test lead to ground. If reading is less than 10.5 volts, repair open in KAPWR circuit. Repeat QUICK TEST  . If code 12 is still displayed, go to next step. If reading is 10.5 volts or more, go to next step.
  9. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Connect ISC motor. Install a jumper wire between test pin No. 21 and 1, and between test pin No. 41 and ground to extend ISC motor shaft. If shaft does not extend 2 in. (51 mm.) or more, replace motor. Repeat QUICK TEST  . If shaft does extend far enough, go to next step.
  10. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Install a jumper wire between test pins No. 41 and 1, and between test pin No. 21 and ground to retract ISC motor shaft. If shaft does not retract, replace motor. Repeat QUICK TEST  . If shaft does retract, go to next step.
  11. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Install a jumper wire between test pins No. 21 and 1, and between test pin No. 41 and ground to extend ISC motor shaft. If shaft does not extend, replace motor and repeat QUICK TEST  . If shaft does extend, replace ECA and repeat QUICK TEST  .
  12. Code 58 Displayed. Turn key off and wait 10 seconds. Press on ISC motor shaft to simulate throttle contact. Perform KOEO SELF-TEST while maintaining pressure on shaft. Check for code 68. Ignore all other codes at this time. If code 68 is displayed, go to step 5). If code 68 is not displayed, go to next step.
  13. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Install a jumper wire between test pins No. 41 and 1, and between test pin No. 21 and ground to retract ISC shaft. If shaft retracts, check ISC motor adjustments. If shaft does not retract, go to next step.
  14. Turn key off and wait 10 seconds. Connect ECA and disconnect harness from ISC. Perform KOEO SELF-TEST. Check for code 68. Ignore all other codes at this time. If code 68 is displayed, replace motor and repeat QUICK TEST  . If code 68 is not displayed, go to next step.
  15. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Leave ISC harness disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between test pin No. 28 (24 on Sable/Taurus) and test pins No. 40, 46, and 60. If any reading is less than 10,000 ohms, repair short to ground. Repeat QUICK TEST  . If all readings are 10,000 ohms or more, replace ECA. Repeat QUICK TEST  .
  16. Code 12 Displayed. If codes 58, 68, 31, or 41 are also displayed, go to KEY ON/ENGINE RUNNING CIRCUIT TEST MENU  table for appropriate test(s). If these codes are not displayed, go to next step.
  17. Check throttle plates and linkage for binding. If vehicle is equipped with cruise control, make sure that cruise control linkage is not binding. If throttle or linkage is binding, repair problem as necessary and repeat QUICK TEST  . If no problem is found with linkage or throttle plates, go to next step.
  18. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Install a jumper wire between test pins No. 21 and 1, and between test pin No. 41 and ground to extend ISC motor shaft. If shaft does not extend, replace motor and repeat QUICK TEST  . If shaft does extend, replace ECA and repeat QUICK TEST  .
  19. Code 13 & 16 Displayed. Prepare vehicle for normal operation. Deactivate SELF-TEST and turn A/C off. Start and run engine at at idle for 30 seconds, then at part throttle for 5 seconds. Repeat this sequence for 3 minutes. If idle speed is erratic, check for vacuum leaks or codes 22, 31, 41, or 58. Repair vacuum leaks and service codes as necessary before going on with test. If idle speed is not erratic, go to next step.
  20. Check throttle plates and linkage for sticking or binding. If any fault is found, repair as necessary and repeat QUICK TEST  . If no fault is found, go to next step.
  21. Perform KOEO SELF-TEST and record service codes. Leave key on. Turn engine off. If code 68 is displayed, go back to step 1). If code 68 is not displayed, check anti-diesel (run-on) speed adjustments.
  22. Turn key off and wait 10 seconds. Install breakout box, leaving ECA disconnected. Disconnect harness from ISC motor and set DVOM on 200,000-ohm scale. Measure resistance between test pin No. 41 and test pins No. 40, 46, and 60. Also measure resistance between test pin No. 21 and test pins No. 40, 46, and 60. If any reading is 10,000 ohms or more, repair bad circuit. Repeat QUICK TEST  . If code 12 is still displayed, replace ECA and repeat QUICK TEST  . If all readings are greater than 10,000 ohms, go to next step.
  23. Turn key on, leaving engine off. Leave breakout box installed and ECA and ISC disconnected. Set DVOM on 20-volt scale. Measure voltage between test pin No. 41 and test pins No. 40 and 60. Also measure voltage between test pin No. 21 and test pins No. 40 and 60. If any reading is one volt or more, repair short circuit to power. Repeat QUICK TEST  . If code 12 is still displayed, replace ECA and repeat QUICK TEST  . If all voltage readings are less than one volt, connect DC motor and go to next step.
  24. Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Connect ISC motor. Install a jumper wire between test pins No. 21 and 1, and between test pin No. 41 and ground to extend ISC motor shaft. If shaft does not extend, replace motor. Repeat QUICK TEST  . If shaft does extend, replace ECA and repeat QUICK TEST  .
Fig 2: Idle Speed Control DC Motor/Idle Tracking Switch Assembly Circuit
G6054
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