Test B: TFT Sensor
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 Mercury Grand Marquis, 2002 Lincoln Town Car, 2002 Ford Crown Victoria, 2001 Mercury Mountaineer, and 2001 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST)
under SELF-DIAGNOSTIC SYSTEM. Ensure all EEC-V systems are working properly and DTCs are no longer present.
- Ensure transmission wiring harness connector is fully seated, and terminals are fully engaged in connector and in good condition. Repair as necessary. Install scan tool. Turn ignition switch to ON position. Follow on screen instructions and select PID/DATA MONITOR AND RECORD. Select PIDs TFT and TFTV. If vehicle enters PID DATA MONITOR AND RECORD mode, remain in PID mode and go to next step. If vehicle will not enter PID mode, repeat procedure. If vehicle is still unable to enter PID mode, see SCAN TOOL UNABLE TO COMMUNICATE under SELF-DIAGNOSTIC SYSTEM.
- While monitoring TFT PIDs, perform the following steps:
- If vehicle is already warmed up or at operating temperature, allow for vehicle to cool down.
- If vehicle is cold, start engine and run until it reaches operating temperature.
If TFT PIDs do not increase with warm up and decrease during cool down, go to next step. If TFT or TFTV PIDs drop in or out of range, inspect for intermittent faults. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If TFT PIDs increase with warm up and decrease with cool down, erase all trouble codes. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM. Diagnose fault by symptom. See SYMPTOM DIAGNOSIS (ELECTRONIC) or SYMPTOM DIAGNOSIS (MECHANICAL) under TROUBLE SHOOTING.
- Drain transmission fluid and remove oil pan. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Ensure internal molded lead frame is not damaged. Repair as necessary. Using DVOM, measure voltage between internal molded lead frame terminal No. 2 and ground. See Fig 1 . If voltage is present, go to next step. If voltage is not present, check for open or short circuit in internal transmission wiring harness.
- Disconnect transmission wiring harness connector. Using DVOM, measure resistance between TFT sensor internal molded lead frame terminals. See Fig 2 . See TFT SENSOR TEMPERATURE/RESISTANCE table. If resistance is not as specified, replace internal molded lead frame and TFT sensor as an assembly. If resistance is as specified, diagnose overheating symptom. See SYMPTOM DIAGNOSIS (ELECTRONIC) or SYMPTOM DIAGNOSIS (MECHANICAL) under TROUBLE SHOOTING.
TFT SENSOR TEMPERATURE/RESISTANCE
| Temperature °F (°C) | K/Ohms |
|---|---|
| -40 To -4 | 284-967 |
| -3 To 31 | 100-284 |
| 32-68 (0-20) | 37-100 |
| 69-104 (21-40) | 16-37 |
| 105-158 (41-70) | 5-16 |
| 159-194 (71-90) | 2.7-5 |
| 195-230 (91-110) | 1.5-2.7 |
| 231-266 (111-130) | .8-1.5 |
| 267-302 (131-150) | .54-.8 |