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Pinpoint Test A: The Speed Control Is Inoperative

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
  1. A1 VERIFY PCM CONFIGURATION 
    • Enter the following diagnostic mode on the diagnostic tool: Programmable Parameters
    • Verify that the speed control is enabled in the PCM.
    • Is the speed control enabled? 
    1. YES  : Go to  A2.
    2. NO  : Enable the speed control in the PCM using the scan tool programmable parameters menu. If no parameter exists, REFER to MODULE CONFIGURATION article to carry out PCM programmable module installation (PMI). TEST the system for normal operation.
  2. A2 CHECK FOR DTCs 
    • Review the recorded DTCs from the PCM self-test.
    • Are any non-speed control DTCs recorded? 
    1. YES  : REFER to the Introduction - Gasoline Engines article. REPAIR all PCM DTCs and RETEST the speed control.
    2. NO  : Go to  A3.
  3. A3 CHECK THE SPEED CONTROL COMMAND SWITCH (SCCS) PID 
    • Start the engine.
    • Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
    • With the engine running, monitor the PCM SCCS PID while pressing the speed control switches as follows:
      Speed Control Switch PID Minimum Value PID Maximum Value
      OFF 0.00 volts 1.089 volts
      SET - 2.192 volts 3.057 volts
      SET + 3.057 volts 3.721 volts
      RESUME 3.721 volts 4.209 volts
      ON 4.209 volts 4.556 volts
      No switch pressed 4.556 volts 4.839 volts
    • Are the PCM SCCS PID values OK? 
    1. YES  : TURN the engine off. Go to  A5.
    2. NO  : TURN the engine off. Go to  A4.
  4. A4 CHECK THE SPEED CONTROL SWITCH 
    • Key in OFF position.
    • Disconnect: PCM C175b
    • Measure the resistance between the PCM C175b-19, circuit 248 (TN/OG), harness side and the PCM C175b-30, circuit 133 (BK), harness side, while pressing the speed control switches as follows:
      Speed Control Switch Resistance Value
      OFF Less than 5 ohms
      SET - 285 - 315 ohms
      SET + 570 - 630 ohms
      RESUME 1,054 - 1,165 ohms
      ON 2,004 - 2,215 ohms
      No switch pressed 4,094 - 4,525 ohms
    • Are the speed control switch resistance values OK? 
    1. YES  : Go to  A11.
    2. NO  : INSTALL a new speed control switch. REFER to Speed Control Switch . TEST the system for normal operation.
  5. A5 CHECK THE STOPLAMP SWITCH (BOO) PID 
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
    • Monitor the PCM BOO PID.
    • Apply and release the brake pedal.
    • Does the PID value agree with the brake pedal position? 
    1. YES  : Go to  A6.
    2. NO  : Go to Pinpoint Test B .
  6. A6 CHECK THE VEHICLE SPEED 
    NOTE: This step may require an assistant.
    • Enter the following diagnostic mode on the diagnostic tool: ABS Module DataLogger
    • Monitor and record the ABS module LF_WSPD (left front wheel speed) PID while driving the vehicle at 48 km/h (30 mph) as indicated on the speedometer.
    • Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
    • Monitor and record the PCM VSS (vehicle speed) PID while driving the vehicle at 48 km/h (30 mph).
    • Does the speed indicated by the ABS module LF_WSPD PID match the PCM VSS PID? 
    1. YES  : If equipped with an automatic transmission, go to  A7.

      If equipped with a manual transmission, go to  A8.

    2. NO  : REFER to the Introduction - Gasoline Engines article to diagnose the output shaft speed (OSS) sensor signal.
  7. A7 CHECK THE DIGITAL TRANSMISSION RANGE (TR) SENSOR PID 
    • Apply the parking brake.
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
    • Monitor the PCM TR PID.
    • Select DRIVE.
    • Does the PID value agree with the transmission range selector lever position? 
    1. YES  : Go to  A11.
    2. NO  : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 5R55S article.
  8. A8 CHECK THE CLUTCH PEDAL SPEED CONTROL DEACTIVATOR SWITCH (CPP_TOP) PID 
    • Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
    • Monitor the PCM CPP_TOP PID while pressing and releasing the clutch pedal.
    • Does the clutch pedal speed control deactivator switch PID agree with the clutch pedal position? 
    1. YES  : Go to  A11.
    2. NO  : Go to  A9.
  9. A9 CHECK CIRCUIT 1205 (BK) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: Clutch Pedal Speed Control Deactivator Switch C277
      • Fig 1: Checking Circuit 1205 (BK) For An Open
      GF0001251Courtesy of FORD MOTOR CO.
    • Measure the resistance between the clutch pedal speed control deactivator switch C277-3, circuit 1205 (BK), harness side and ground.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  A10.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  10. A10 CHECK CIRCUIT 1899 (WH) FOR AN OPEN OR A SHORT TO GROUND 
    • Disconnect: PCM C175b
      • Fig 2: Measuring Resistance Between PCM C175B-39, Circuit 1899 (WH), Harness Side
      GF0001252Courtesy of FORD MOTOR CO.
    • Measure the resistance between the PCM C175b-39, circuit 1899 (WH), harness side and the clutch pedal speed control deactivator switch C277-1, circuit 1899 (WH), harness side; and between the PCM C175b-39, circuit 1899 (WH), harness side and ground.
    • Is the resistance less than 5 ohms between the PCM and the clutch pedal speed control deactivator switch, and greater than 10,000 ohms between the PCM and ground? 
    1. YES  : INSTALL a new clutch pedal speed control deactivator switch. REFER to Speed Control Deactivator Switch . TEST the system for normal operation.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  11. A11 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Check for:
      • corrosion
      • damaged pins
      • pushed-out pins
    • Connect all the PCM connectors and make sure they seat correctly.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    1. YES  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS article. TEST the system for normal operation.
    2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
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