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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 2099 (Automatic Transmission - Cd4E) >> Diagnostic Tests >> Pinpoint Tests - Non 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 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Refer to the Transaxle Vehicle Harness Connector illustration preceding these pinpoint tests.
  1. B1 CHECK FOR REFERENCE VOLTAGE AT THE TRANSAXLE VEHICLE HARNESS CONNECTOR 
    CAUTION: Do not pry on the connector. This will damage the connector and may result in a transaxle concern. Press button and pull up on the transaxle vehicle harness connector.
    • Key in OFF position.
    • Disconnect: Transaxle Connector C199
    • Key in ON position.
    • Use a mirror to inspect both ends of the connector for damaged or pushed-out pins, corrosion, loose wires and missing or damaged seals.
    • Measure the voltage between transaxle vehicle harness connector C199-2, circuit RE406 (GY/VT) and ground.
      • Fig 1: Measuring Voltage
      GF0042336Courtesy of FORD MOTOR CO.
    • Is the voltage between 4.75 and 5.25 volts? 
    1. YES  : Go to  B4.
    2. NO  : Go to  B2.
  2. B2 CHECK THE REFERENCE VOLTAGE CIRCUIT FOR A SHORT TO GROUND OR POWER 
    • Key in OFF position.
    • Disconnect: PCM Connector C175T
    • Inspect the PCM connector for damage. Make sure the pins are fully engaged and in good condition before proceeding.
    • Key in ON position.
    • Measure the resistance between transaxle vehicle harness connector C199-2, circuit RE406 (GY/VT) and C199-3, circuit CBB24 (VT/GN) and ground.
      • Fig 2: Measuring Resistance
      GF0042337Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  B3.
    2. NO  : REPAIR circuit RE406 (GY/VT) for a short. CONNECT all components. TEST the system for normal operation.
  3. B3 CHECK THE REFERENCE VOLTAGE CIRCUIT FOR AN OPEN 
    • Measure the resistance between PCM electrical connector C175T-41, circuit RE406 (GY/VT) and transaxle electrical connector C199-2, circuit RE406 (GY/VT).
      • Fig 3: Checking Circuit For Open
      GF0024711Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : Circuit RE406 (GY/VT) may have an intermittent open or short. REPEAT test steps B2 and B3 while wiggling the wiring harness. INSPECT the vehicle wiring harness for damage and repair as necessary. If damage is not found in the wiring harness, install a new PCM.
    2. NO  : REPAIR circuit RE406 (GY/VT) for an open. CONNECT all components. TEST the system for normal operation.
  4. B4 CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND OR POWER 
    • Disconnect: PCM Connector C175T
    • Inspect the PCM connector for damage. Make sure the pins are fully engaged and in good condition before proceeding.
    • Key in ON position.
    • Measure the resistance between transaxle vehicle harness connector C199-1, circuit VET27 (BN/YE) and C199-3, circuit CBB24 (VT/GN) and ground.
      • Fig 4: Measuring Resistance
      GF0042338Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  B5.
    2. NO  : REPAIR circuit VET27 (BN/YE) for a short. CONNECT all components. TEST the system for normal operation.
  5. B5 CHECK THE SIGNAL CIRCUIT FOR AN OPEN 
    • Measure the resistance between PCM electrical connector C175T-29, circuit VET27 (BN/YE) and transaxle electrical connector C199-1, circuit VET27 (BN/YE).
      • Fig 5: Measuring Resistance
      GF0042339Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  B6.
    2. NO  : REPAIR circuit VET27 (BN/YE) for an open. CONNECT all components. TEST the system for normal operation.
  6. B6 CHECK THE RESISTANCE OF THE TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR 
    • Measure the resistance between pin 2 and pin 1 of transaxle vehicle harness connector C199, component side.
      • Fig 6: Measuring Resistance
      GF0042340Courtesy of FORD MOTOR CO.
    • Compare the resistance with the following table.
      TRANSMISSION FLUID TEMPERATURE

      °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° 159°-230° 2.7K-1.5K
      111°-130° 231°-266° 1.5K-0.8K
      131°-150° 267°-302° 0.8K-0.54K
    • Is the resistance within range? 
    1. YES  : Go to  B7.
    2. NO  : INSTALL a new main control assembly. REFER to Main Control Valve Body .
  7. B7 CHECK FOR PCM COMMUNICATION 
    • Connect: PCM Connector C175T
    • Connect: Transaxle Connector C199
    • Connect the diagnostic tool.
    • Monitor the TFT PID.
    • Is the TFT PID temperature displayed on the scan tool? 
    1. YES  : Go to  B8.
    2. NO  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - 2.3L article or ELECTRONIC ENGINE CONTROLS - 3.0L (4V) article. CONNECT all components. TEST the system for normal operation.
  8. B8 CHECK FOR AN ERRATIC OR INTERMITTENT OPEN TFT SENSOR SIGNAL 
    • While monitoring the TFT PID, carry out the following test: If transmission is cold, run transmission to warm it up. If transmission is warm, allow transmission to cool down.
    • Does the TFT PID temperature increase or decrease erratically as the transmission warms or cools or does the TFT voltage drop in and out of range? 
    1. YES  : INSTALL a new main control assembly. REFER to Main Control Valve Body .
    2. NO  : REFER to Diagnosis By Symptom  to diagnose transaxle overheating.
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