Pinpoint Test C: The Speed Control Is Inoperative - No DTCS

C1 CHECK THE HORN SYSTEM
- Verify the horn system operates by pressing the horn switch.
- Does the horn system operate correctly?
- Yes : GO to C2 .
- No : REFER to HORN to continue diagnosis of the horn.
C2 CHECK THE SPEED CONTROL ON SWITCH
- Key in OFF position.
- Disconnect: Speed Control Actuator C122.
- Key in ON position.
- Measure the voltage between the speed control actuator C122-5, circuit 151 (LB/BK), harness side and ground while pressing the speed control ON switch.
  
  Fig 1: Measuring Voltage Between Speed Control Actuator C122-5, Circuit 151 (LB/BK), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to C3 .
- No : GO to C4.
C3 CHECK THE SET/ACCEL SWITCH
- Key in OFF position.
- Measure the resistance between the speed control actuator C122-5, circuit 151 (LB/BK), harness side and the speed control actuator C122-6, circuit 848 (DG/OG), harness side while pressing the speed control SET/ACCEL switch.
  
  Fig 2: Measuring Resistance Between Speed Control Actuator C122-5 And Speed Control Actuator C122-6, Circuit 848
  Courtesy of FORD MOTOR CO.
- Is the resistance between 612-748 ohms with the switch pressed and greater than 10,000 ohms with the switch released?
- Yes : GO to C6.
- No : INSTALL a new speed control switch. REFER to SPEED CONTROL SWITCH - WITH REMOTE AUDIO CONTROLS or SPEED CONTROL SWITCH - WITHOUT REMOTE AUDIO CONTROLS . TEST the system for normal operation.
C4 CHECK CIRCUIT 151 (LB/BK) FOR AN OPEN
- Disconnect: Clockspring C218b.
- Measure the resistance between the speed control actuator C122-5, circuit 151 (LB/BK), harness side and the clockspring C218b-6, circuit 151 (LB/BK), harness side.
  
  Fig 3: Measuring Resistance Between Speed Control Actuator C122-5 And Clockspring C218b-6
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to C5 .
- No : REPAIR the circuit. TEST the system for normal operation.
C5 CHECK THE CLOCKSPRING
- Measure the resistance between the clockspring C218b-6, component side and the upper clockspring pin 1, component side.
  
  Fig 4: Measuring Resistance Between Clockspring C218b-6, Component Side And Upper Clockspring Pin 1, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : INSTALL a new speed control switch. REFER to SPEED CONTROL SWITCH - WITH REMOTE AUDIO CONTROLS or SPEED CONTROL SWITCH - WITHOUT REMOTE AUDIO CONTROLS . TEST the system for normal operation.
- No : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
C6 CHECK CIRCUIT 601 (LB/PK) AND CIRCUIT 535 (LB/RD) FOR VOLTAGE
- Key in ON position.
- Measure the voltage between the speed control actuator C122-7, circuit 601 (LB/PK), harness side and ground; and between the speed control actuator C122-9, circuit 535 (LB/RD), harness side and ground.
  
  Fig 5: Measuring Voltage Between Speed Control Actuator C122-7, Circuit 601 (LB/PK), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
- Yes : GO to C7 .
- No : REPAIR the circuit in question. TEST the system for normal operation.
C7 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the speed control actuator C122-10, circuit 1205 (BK), harness side and ground.
  
  Fig 6: Measuring Resistance Between Speed Control Actuator C122-10, Circuit 1205 (BK), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to C8 .
- No : REPAIR the circuit. TEST the system for normal operation.
C8 CHECK FOR CORRECT SPEED CONTROL ACTUATOR OPERATION
- Disconnect the speed control actuator connector.
- Check for:
  - corrosion
  - pushed-out pins
- Connect the speed control actuator connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new speed control actuator. REFER to SPEED CONTROL ACTUATOR . TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.