Pinpoint Test D: The Transmission Control Switch (TCS) Does Not Operate Correctly

D1 CHECK THE OVERDRIVE OFF INDICATOR ILLUMINATION
- Key in OFF position.
- Connect the diagnostic tool.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Powertrain Control Module PID.
  Select and monitor the PCM PID for the overdrive OFF indicator while cycling the transmission control switch (TCS).
- Does the PID agree with the TCS position?
- Yes : GO to D2.
- No : GO to D3.
D2 CHECK CIRCUIT 911 (WH/LG) FOR AN OPEN BETWEEN THE INSTRUMENT CLUSTER AND THE PCM
- Key in OFF position.
- Disconnect: Powertrain Control Module C185.
- Disconnect: Instrument Cluster (C250 Conventional) (C255 Electronic).
- Connect the EEC-V 104-Pin Breakout Box. Leave the PCM disconnected.
- For the conventional instrument cluster, measure the resistance between instrument cluster C250 pin 3, circuit 911 (WH/LG), harness side and EEC-V 104-Pin Breakout Box pin 12, circuit 911 (WH/LG), harness side.
  
  Fig 1: Checking Circuit 911 (WH/LG) For Open Between Instrument Cluster And PCM (1 Of 2)
  Courtesy of FORD MOTOR CO.
- For the electronic instrument cluster, measure the resistance between instrument cluster C255 pin 14, circuit 911 (WH/LG), harness side and EEC-V 104-Pin Breakout Box pin 12, circuit 911 (WH/LG), harness side.
  
  Fig 2: Checking Circuit 911 (WH/LG) For Open Between Instrument Cluster And PCM (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : For the conventional instrument cluster, INSTALL a new instrument cluster printed circuit. REFER to INSTRUMENT CLUSTER - CONVENTIONAL . For the electronic instrument cluster, INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER - ELECTRONIC . REINSTALL all components. TEST the system for normal operation.
- No : REPAIR circuit 911 (WH/LG). REINSTALL all components. TEST the system for normal operation.
D3 CHECK THE POWER SUPPLY TO PCM - CIRCUIT 224 (TN/WH)
- Key in OFF position.
- Disconnect: Powertrain Control Module C185.
- Connect the EEC-V 104-Pin Breakout Box. Leave the PCM disconnected.
- Key in ON position.
- Measure the voltage between EEC-V 104-Pin Breakout Box pin 29, circuit 224 (TN/WH), harness side and ground with the TCS in the ON position.
  
  Fig 3: Measuring Voltage Between EEC-V 104-Pin Breakout Box Pin 29, Circuit 224 (TN/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : INSTALL a new PCM. REINSTALL all components. TEST the system for normal operation.
- No : GO to D4.
D4 CHECK THE POWER SUPPLY TO THE TCS - CIRCUIT 640 (RD/YE)
- Key in OFF position.
- Disconnect: Transmission Control Switch C202.
- Key in ON position.
- Measure the voltage between TCS C202 pin 2, circuit 640 (RD/YE), harness side and ground.
  
  Fig 4: Measuring Voltage Between TCS C202 Pin 2, Circuit 640 (RD/YE), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to D5.
- No : REPAIR circuit 640 (RD/YE). REINSTALL all components. TEST the system for normal operation.
D5 CHECK CIRCUIT 224 (TN/WH) FOR AN OPEN BETWEEN THE PCM AND THE TCS
- Key in OFF position.
- Measure the resistance between TCS C202 pin 1, circuit 224 (TN/WH), harness side and EEC-V 104-Pin Breakout Box pin 29, circuit 224 (TN/WH), harness side; and between TCS C202 pin 1, circuit 224 (TN/WH), harness side and ground.
  
  Fig 5: Checking Circuit 224 (TN/WH) For Open Between PCM And TCS
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the TCS and the PCM, and greater than 10,000 ohms between the TCS and ground?
- Yes : INSTALL a new TCS. REFER to SELECTOR LEVER - COLUMN SHIFTER . REINSTALL all components. TEST the system for normal operation.
- No : REPAIR the circuit 224 (TN/WH). REINSTALL all components. TEST the system for normal operation.