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Test B: Set Speed Fluctuates

  1. Check If Condition Occurs Only While Using Speed Control  - Ensure engine is properly tuned. Ensure problem does not occur while driving vehicle without speed control activated. If problem occurs without speed control activated, repair engine as necessary. If problem occurs only with speed control activated, go to next step.
  2. Check For Binding In Speed Control Cable & Throttle Body Linkage  - Check for binding or sticking speed control servo/actuator cable, throttle linkage and/or throttle plate. Ensure throttle cable bracket and speed control servo/actuator bracket are not loose. Repair as necessary. Test drive vehicle to check operation. If all components are okay, go to next step.
  3. Check Vehicle Speed Sensor (VSS)  - Disconect VSS connector C129 (located on left rear of transmission). Using an ohmmeter, check resistance between VSS terminals. If resistance is 200-300 ohms, check for open or short in Gray/Black wire and Pink/Orange wire. Repair as necessary and go to next step. If resistance is not 200-300 ohms, replace VSS and retest system operation.
  4. Check Speed Control Servo/Actuator  - Substitute a known-good speed control servo/actuator. Test drive vehicle and check for proper speed control operation. If speed control operates properly, replace original speed control servo/actuator and retest system operation. If speed control servo/actuator does not operate properly, check PCM for stored codes. See appropriate G - TESTS W/CODES article in the ENGINE PERFORMANCE section.
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