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Test A: Speed Control Is Inoperative

  1. Turn ignition switch to LOCK position. Disconnect speed control servo/actuator harness connector C136. Turn ignition switch to RUN position. Measure voltage between terminals No. 7 (White/Light Blue wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136. See Fig 1 . If battery voltage does not exist, go to next step. If battery voltage exists, go to step  3 .
  2. Turn ignition switch to LOCK position. Measure resistance between ground and terminal No. 10 (Black wire) at speed control servo/actuator harness connector C136. If resistance is 5 ohms or less, repair power distribution circuit. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS. If resistance is greater than 5 ohms, repair open in Black wire.
  3. Measure voltage between terminals No. 9 (Orange wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136. If battery voltage does not exist, go to next step. If battery voltage exists, go to step  6 .
  4. Disconnect deactivator switch harness connector C261. Measure voltage at Light Green/Red wire terminal at deactivator switch harness connector C261. If battery voltage exists, go to next step. If battery voltage does not exist, repair power distribution circuit. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
  5. Measure resistance in Orange wire between deactivator switch harness connector C261 and terminal No. 9 at speed control servo/actuator harness connector C136. If resistance is 5 ohms or less, replace deactivator switch. If resistance is greater than 5 ohms, repair open in Orange wire.
  6. Measure voltage between terminals No. 5 (Light Blue/Black wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136 while pressing speed control switch ON button. If battery voltage does not exist, go to next step. If battery voltage exists, go to step  9 .
  7. Disconnect air bag sliding contact harness connector C233. Measure resistance in Light Blue/Black wire between air bag sliding contact harness connector C233 and terminal No. 5 at speed control servo/actuator harness connector C136. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Light Blue/Black wire.
  8. Remove driver's side air bag. See appropriate AIR BAG RESTRAINT SYSTEMS article. Disconnect speed control switch harness connector C243. Measure resistance between pin No. 1 at air bag sliding contact connector C233 (component side) and pin No. 1 at speed control switch harness connector C243 (air bag sliding contact side). See Fig 2 . If resistance is 5 ohms or less, replace speed control switch. If resistance is greater than 5 ohms, replace air bag sliding contact.
  9. Turn ignition switch to RUN position. Measure voltage between terminals No. 5 (Light Blue/Black wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136. If no voltage exists, go to next step. If any voltage exists, go to step  12 .
  10. Turn ignition switch to LOCK position. Disconnect air bag sliding contact harness connector C233. Turn ignition switch to RUN position. Measure voltage between terminals No. 5 (Light Blue/Black wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136. If no voltage exists, go to next step. If any voltage exists, repair short to voltage in Light Blue/Black wire.
  11. Turn ignition switch to LOCK position. Disconnect speed control switch harness connector C243. Turn ignition switch to RUN position. Measure voltage at pin No. 1 at air bag sliding contact connector C233 (component side). See Fig 2 . If no voltage exists, replace speed control switch. If any voltage exists, replace air bag sliding contact.
  12. Turn ignition switch to LOCK position. Measure resistance between terminals No. 5 (Light Blue/Black wire) and No. 6 (Dark Green/Orange wire) at speed control servo/actuator harness connector C136 while pressing SET/ACCEL button. If resistance is 612-748 ohms, go to next step. If resistance is not 612-748 ohms, replace speed control switch.
    NOTE: Ensure brake lights are operating properly before proceeding.
  13. Measure voltage between terminals No. 4 (Light Green wire) and No. 10 (Black wire) at speed control servo/actuator harness connector C136. When brake pedal is depressed, battery voltage should exist. When brake pedal is not depressed, no voltage should exist. If voltage is as specified, go to step  16 . If voltage is not as specified, go to next step (M/T) or repair open in Light Green wire (A/T).
  14. Disconnect clutch pedal position switch harness connector C260. Measure voltage at appropriate Light Green wire terminal at clutch pedal position switch harness connector C260. When brake pedal is depressed, battery voltage should exist. When brake pedal is not depressed, no voltage should exist. If voltage is as specified, go to next step. If voltage is not as specified, repair open in Light Green wire.
  15. Measure resistance in Light Green wire between clutch pedal position switch harness connector C260 and terminal No. 4 at speed control servo/actuator harness connector C136. If resistance is 5 ohms or less, replace clutch pedal position switch. If resistance is greater than 5 ohms, repair open in Light Green wire.
  16. Turn ignition switch to LOCK position. Disconnect Powertrain Control Module (PCM) harness connector C294. Measure resistance in White/Orange wire between terminal No. 3 at speed control servo/actuator harness connector C136 and terminal No. 68 at PCM harness connector C294. See Fig 2 and Fig 3 . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in White/Orange wire.
  17. Install known good speed control servo/actuator. Test drive vehicle and check for proper speed control operation. If speed control operates properly, replace speed control servo/actuator. If speed control does not operate properly, replace PCM.
Fig 1: Identifying Servo/Actuator harness connector C136 Terminals
G96B29331Courtesy of FORD MOTOR CO.
Fig 2: Testing Air Bag Sliding Contact Resistance
G99H08207Courtesy of FORD MOTOR CO.
Fig 3: Identifying PCM Harness Connector C294 Terminals
G96F31315Courtesy of FORD MOTOR CO.
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