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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 2549 (Automatic Transmission - Automatic Transaxle/Transmission - 4R70E/4R75E) >> 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 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Refer to the Transmission Internal Harness Connector illustration in Transmission Connector Layouts .
  1. B1 ELECTRONIC DIAGNOSTICS 
    • Vehicle in PARK.
    • Key in OFF position.
    • Check to make sure the transmission harness connector is fully seated, pins are fully engaged in connector and in good condition before proceeding.
    • Connect the diagnostic tool.
    • Key in ON position.
    • Access the transmission PIDs.
    • Is the scan tool able to access the transmission PIDs? 
    1. YES  : Go to  B2.
    2. NO  : REPEAT procedure to access the transmission PIDs. If the scan tool did not access the transmission PIDs, REFER to the Introduction - Gasoline Engines article for diagnosis of PCM.
  2. B2 WARM-UP/COOL-DOWN CYCLE 
    • While monitoring the TFT PIDs, carry out the following test: If transmission is cold, run transmission to warm it up. If transmission is warm, allow transmission to cool down.
    • Do the TFT PIDs increase as the transmission is warmed up or decrease as the transmission is cooled, or does the TFT or TFT voltage drop in and out of range? 
    1. YES  : If the TFT PIDs increase as the transmission is warmed or decrease as the transmission is cooled, CLEAR all DTCs. ROAD TEST to verify if concern is still present. If concern is still present, REFER to Diagnosis By Symptom  to diagnose transmission overheating.

      If the TFT or TFT voltage drop in and out of range, INSPECT for intermittent concern in the internal/external harness, sensor or connector.

    2. NO  : Go to  B3.
  3. B3 ELECTRICAL SIGNAL CHECK 
    • Key in ON position.
    • Remove transmission fluid pan.
    • Visually inspect the lead frame and connectors for damage.
      • Fig 1: Measuring Voltage
      GF0003442Courtesy of FORD MOTOR CO.
    • Measure the voltage with the positive lead to positive TFT at sensor pin and negative lead to a good ground.
    • Is any voltage present? 
    1. YES  : Go to  B4.
    2. NO  : CHECK for open or short circuit in vehicle harness, internal harness or a PCM concern.
  4. B4 CHECK THE RESISTANCE OF THE TFT SENSOR 
    • Disconnect: Transmission Harness
      • Fig 2: Measuring Resistance
      GF0003443Courtesy of FORD MOTOR CO.
    • Measure the resistance between the positive TFT and negative TFT pins at transmission connector, using the following:
      TRANSMISSION FLUID TEMPERATURE (TFT)

      °C °F Resistance (Ohms)
      -40 to -20 -40 to -4 967K-284K
      -19 to -1 -3 to 31 284K-100K
      0-20 32-68 100K-37K
      21-40 69-104 37K-16K
      41-70 105-158 16K-5K
      71-90 159-194 5K-2.7K
      91-110 195-230 2.7K-1.5K
      111-130 231-266 1.5K-0.8K
      131-150 267-302 0.8K-0.54K
    • Is the resistance correct? 
    1. YES  : REFER to Diagnosis By Symptom  to diagnose an overheating concern.
    2. NO  : INSTALL a new internal harness (sensor is part of harness).
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