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Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1083 (Automatic Transmission) >> Diagnostic Tests >> Pinpoint Tests - OSC Equipped Vehicle >> Pinpoint Tests >> Pinpoint Test B: Transmission Fluid Temperature (TFT) Sensor

Pinpoint Test B: Transmission Fluid Temperature (TFT) Sensor

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Refer to the Transaxle Vehicle Harness Connector illustration Transaxle Connector Layouts .
NOTE: Refer to the Transaxle Internal Harness Diagram illustration Transaxle Connector Layouts .
  1. B1 ELECTRONIC DIAGNOSTICS 
    • Check to make sure the transaxle vehicle harness connector C168 is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
    • Have the above items been checked? 
    1. YES  : Go to  B2.
    2. NO  : CARRY OUT checks. ERASE the codes. REPEAT the Self Test.
  2. B2 CHECK THE TFT SENSOR CIRCUITS FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: Transaxle Vehicle Harness Connector C168
    • Disconnect: PCM Transaxle Electrical Connector C175t
    • Use a mirror to inspect both ends of the connector for damage or pushed-out pins, corrosion, loose wires and missing or damaged seals.
      • Fig 1: Measuring Resistance Between PCM Transaxle Electrical Connector C175T-20 & C168-2, Circuit VET27 (BN/YE)
      GF0031606Courtesy of FORD MOTOR CO.
    • Measure the resistance between PCM transaxle electrical connector C175t-20, circuit VET27 (BN/YE) and transaxle vehicle harness connector C168-2 circuit VET27 (BN/YE).
      • Fig 2: Measuring Resistance Between PCM Transaxle Electrical Connector C175T-43 & C168-3, Circuit RE406 (GY/VT)
      GF0031607Courtesy of FORD MOTOR CO.
    • Measure the resistance between PCM transaxle electrical connector C175t-43, circuit RE406 (GY/VT) and transaxle vehicle harness connector C168-3, circuit RE406 (GY/VT).
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  B3.
    2. NO  : REPAIR the circuit(s) for an open. CONNECT all components. TEST the system for normal operation.
  3. B3 CHECK THE TFT SENSOR CIRCUITS FOR A SHORT TO GROUND 
      Fig 3: Measuring Resistance Between Transaxle Vehicle Harness Connector C168 Pins 2 & 3, Circuit VET27 (BN/YE) & RE406 (GY/VT)
      GF0031608Courtesy of FORD MOTOR CO.
    • Measure the resistance between transaxle vehicle harness connector C168 pins 2, circuit VET27 (BN/YE) and 3, circuit RE406 (GY/VT) and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  B4.
    2. NO  : REPAIR the circuit(s) for a short to ground. CONNECT all components. TEST the system for normal operation.
  4. B4 CHECK THE TFT CIRCUITS FOR A SHORT TO VPWR 
      Fig 4: Measuring Voltage Between Transaxle Vehicle Harness Connector C168 Pins 2 & 3, Circuit VET27 (BN/YE) & RE406 (GY/VT)
      GF0031609Courtesy of FORD MOTOR CO.
    • Measure the voltage between transaxle vehicle harness connector C168 pins 2, circuit VET27 (BN/YE) and 3, circuit RE406 (GY/VT) and ground.
    • Is any voltage present? 
    1. YES  : REPAIR the circuit(s) for a short to voltage. CONNECT all components. TEST the system for normal operation.
    2. NO  : Go to  B5.
  5. B5 CHECK THE RESISTANCE OF THE TFT SENSORS/HARNESS 
    • Vehicle must be at normal operating temperature.
    • Connect: Transaxle Vehicle Harness Connector C168
    • TEST 1. 
      • Fig 5: Measuring Resistance Between PCM Transaxle Electrical Connector C175T Pins 20 & 43, Circuit VET27 (BN/YE) & RE406 (GY/VT)
      GF0031610Courtesy of FORD MOTOR CO.
    • Measure and record the resistance between PCM transaxle electrical connector C175t pins 20, circuit VET27 (BN/YE) and 43, circuit RE406 (GY/VT).
    • Compare the resistance value to the following table ranges:
      TRANSMISSION FLUID TEMPERATURE

      °C °F Resistance (Ohms)
      -40 to -20 -40 to -4 1076 K - 269 K
      -19 to -1 -3 to 31 309 K - 91 K
      0 to 20 32-68 104 K - 35 K
      21 to 40 69-104 40 K - 15 K
      41 to 70 105-158 17 K - 4.9 K
      71 to 90 159-194 5.6 K - 2.5 K
      91 to 110 195-230 3.0 K - 1.4 K
      111 to 130 231-266 1.7 K - 0.8 K
      131 to 150 267-302 0.97 K - 0.56 K
    • TEST 2. 
    • Check for intermittent short or open.
    • If the resistance was between 0.8 K and 100 K ohms carry out the following test. If the transaxle is warm, allow it to cool. Check the transmission fluid temperature sensor resistance again. Compare the resistance with the initial resistance. The resistance should decrease if the transaxle was heated and should increase if the transaxle was allowed to cool. If correct, then change in the resistance occurs, repeat On-Board Diagnostic.
    • Is the resistance in the range? 
    1. YES  : INSTALL a new PCM. CONNECT all components. TEST the system for normal operation.
    2. NO  : INSTALL a new solenoid body. REFER to Solenoid Body Assembly . RECONNECT all components. TEST the system for normal operation.
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