LEMON Manuals: Even more car manuals for everyone
Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 761 (Automatic Transmission External Controls - F150 & Mark LT) >> Diagnostic Tests >> External Controls >> Pinpoint Tests >> Pinpoint Test B: The Transmission Control Switch Is Not Operating Correctly

Pinpoint Test B: The Transmission Control Switch Is Not Operating Correctly

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
  1. B1 CHECK FUSE F15 (5A) 
    • Key in OFF position.
    • Check fuse: Central Junction Box (CJB) Fuse F15 (5A)
    • Is the resistance less than 5 ohms? 
    1. YES  : REINSTALL the fuse. Go to  B3 .
    2. NO  : INSTALL a new fuse. TEST the system for normal operation. If the fuse fails again, go to  B2 .
  2. B2 CHECK TRANSMISSION CONTROL (TC) SWITCH CIRCUIT FOR SHORT TO GROUND 
    • Disconnect: Instrument Cluster Connector C220B
    • Inspect for damaged or pushed-out pins, corrosion and loose wires. Repair as necessary.
    • Measure the resistance between transmission control (TC) switch connector pin 1 and ground.
      • Fig 1: Checking Transmission Control (TC) Switch Circuit For Short To Ground
      GF0003757Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  B5.
    2. NO  : REPAIR the circuit. TEST the system for normal operation.
  3. B3 CHECK TC SWITCH CIRCUIT FOR OPEN 
    • Inspect for damaged or pushed-out pins, corrosion and loose wires. Repair as necessary.
    • Measure the resistance between the output side of F15 (5A) and TC switch connector pin 1.
      • Fig 2: Checking TC Switch Circuit For Open
      GF0003758Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  B4.
    2. NO  : REPAIR circuit. RECONNECT all components. TEST the system for normal operation.
  4. B4 CHECK TC SWITCH FOR OPEN 
    • Measure the resistance between TC switch pins 1 and 2 while cycling the switch ON and OFF.
      • Fig 3: Checking TC Switch For Open
      GF0003759Courtesy of FORD MOTOR CO.
    • Is the resistance of the switch greater than 10,000 ohms while OFF and less than 5 ohms while ON? 
    1. YES  : Go to  B6.
    2. NO  : INSTALL a new TC switch. TEST the system for normal operation.
  5. B5 CHECK TC SWITCH FOR SHORT TO GROUND 
    • Measure the resistance between TC switch pins 1 and 2 and ground while cycling the switch.
      • Fig 4: Checking TC Switch For Short To Ground
      GF0003760Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms at any time for either pin? 
    1. YES  : INSTALL a new transmission control switch. RECONNECT all components. TEST the system for normal operation.
    2. NO  : Go to  B7.
  6. B6 CHECK TC SWITCH CIRCUIT FOR OPEN 
    • Measure the resistance between TC switch connector pin 2 and PCM connector pin 45.
      • Fig 5: Checking TC Switch Circuit For Open
      GF0003761Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : INSTALL a new PCM. TEST the system for normal operation.
    2. NO  : REPAIR circuit. RECONNECT all components. TEST the system for normal operation.
  7. B7 CHECK TC SWITCH CIRCUIT FOR SHORT TO GROUND 
    • Measure the resistance between PCM connector pin 45 and ground.
      • Fig 6: Checking TC Switch Circuit For Short To Ground
      GF0003762Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : INSTALL a new PCM. TEST the system for normal operation.
    2. NO  : REPAIR circuit. RECONNECT all components. TEST the system for normal operation.
scientia non olet · About LEMON Manuals