Pinpoint Test A: The Speed Control is Inoperative

2005 Ford Crown Victoria Special EditionSECTION Pinpoint Test A: The Speed Control is Inoperative
  1. A1 RETRIEVE THE RECORDED POWERTRAIN CONTROL MODULE (PCM) DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND SELF-TESTS 
    • Check for recorded PCM DTCs from the continuous and on-demand self-tests.
    • Are any DTCs recorded? 
  2. A2 CHECK THE SPEED CONTROL SWITCHES 
    • Key in OFF position.
    • Disconnect: PCM C175b.
    • Measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and the PCM C175b-30, circuit 848 (DG/OG), harness side while pressing the speed control buttons as follows:
      SPEED CONTROL SWITCHES RESISTANCE SPECIFICATION

      Speed Control Switch Resistance Value
      OFF Less than 5 ohms
      COAST 276 - 324 ohms
      SET/ ACCEL 552 - 648 ohms
      RESUME 1,021 - 1,199 ohms
      ON 1,941 - 2,278 ohms
      No switch pressed 3,965 - 4,655 ohms
      Fig 1: Measuring Resistance Between PCM Connector Terminals
      G03883120Courtesy of FORD MOTOR CO.
    • Are the speed control switch resistance values OK? 
    • Yes  : GO to  A3.
    • No  : INSTALL a new speed control switch. REFER to SPEED CONTROL SWITCH . TEST the system for normal operation.
  3. A3 CHECK THE DIGITAL TRANSMISSION RANGE (TR) SENSOR 
    • Connect: PCM C175b.
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: PID Data Monitor and Record.
    • Monitor the TR sensor PID.
    • Select DRIVE.
    • Does the PID value agree with the transmission range selector lever position? 
  4. A4 CHECK THE DIGITAL TR SENSOR FOR CORRECT ALIGNMENT 
    WARNING: If equipped with fire suppression system, depower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM .
    • Yes  : GO to  A5.
    • No  : ADJUST the digital TR sensor. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION . If equipped with fire suppression system, GO to  A7. TEST the system for normal operation.
  5. A5 CHECK THE VEHICLE SPEED 
    NOTE: This step may require an assistant
    • Enter the following diagnostic mode on the diagnostic tool: Anti-Lock Brake System (ABS) Wheel Speed PID.
    • Monitor and record the ABS module 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 Vehicle Speed PID.
    • Monitor and record the PCM vehicle speed PID while driving the vehicle at 48 km/h (30 mph).
    • Does the speed indicated by the ABS module wheel speed PID match the PCM vehicle speed PID? 
  6. A6 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Check for:
      • corrosion
      • 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? 
    • Yes  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . If equipped with fire suppression system, GO to  A7. 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. If equipped with fire suppression system, GO to  A7.
  7. A7 REPOWER THE FIRE SUPPRESSION SYSTEM 
    WARNING: If equipped with fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM .
    • Verify that the fire suppression system is repowered. For additional information, refer to FIRE SUPPRESSION SYSTEM .
    • Is the fire suppression system repowered? 
    • Yes  : Fire suppression system repowering is complete.
    • No  : REFER to FIRE SUPPRESSION SYSTEM for fire suppression system depowering and repowering procedure.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.