LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 4 (Automatic Transmission - Diagnosis - Ax4S) >> System Tests >> Test B: Transmission Fluid Temperature Sensor

Test B: Transmission Fluid Temperature Sensor

WARNING: This page is about a different variant/trim than selected.

  1. Electronic Diagnostics

    Check transaxle harness connector. Inspect connector for damaged terminals, corrosion and loose wires. Ensure transaxle connector is fully seated. Repair as necessary. Go to next step.

  2. Check Electrical Signal Operation

    Ensure ignition switch is turned to OFF position. Disconnect transaxle harness connector. Using DVOM, connect positive lead to transaxle harness connector terminal No. 5 and negative lead to terminal No. 9. See Figure . Turn ignition switch to ON position. If voltage is 4.75-5.25 volts, go to step  6 . If voltage is not within specification, go to next step.

  3. Check Continuity Of TFT Sensor Signal Return (SIG RTN) Circuits

    Turn ignition switch to OFF position. Disconnect PCM 104-pin connector, and inspect it for damaged terminals, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. Measure and record resistance between breakout box test pin No. 37 and transaxle harness connector terminal No. 5. See Figure . Measure and record resistance between test pin No. 91 and transaxle harness connector terminal No. 9. If each resistance is less than 5 ohms, go to next step. If any resistance is more than 5 ohms, repair open circuit. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Repeat QUICK TEST  under DIAGNOSIS & TESTING.

  4. Check TFT Sensor Circuit For Short To VPWR & Ground

    Ensure ignition switch is turned to OFF position. Disconnect PCM 104-pin connector, and inspect it for damaged terminals, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. Measure and record resistance between breakout box test pin No. 37 and test pins No. 71 and 97. Measure and record resistance between test pin No. 37 and test pins No. 24, 51, 76, 77, 91, 103 and ground. If any resistance is more than 10 k/ohms, go to next step. If any resistance is 10 k/ohms or less, repair short circuit. Disconnect breakout box and clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Road test vehicle. Repeat QUICK TEST  under DIAGNOSIS & TESTING.

  5. Check Resistance Of TFT Sensor/Harness

    Install transmission tester. Set tester Bench/Drive switch to BENCH position. Set solenoid select switch to OHMS CHECK. Connect ohmmeter leads to appropriate TFT jacks. Measure and record resistance. Resistance should be within specification. See TFT SENSOR TEMPERATURE/RESISTANCE  table. If resistance readings are within specification for specific temperature, either warm up transaxle or allow transaxle to cool to measure resistance at different temperatures. If resistance readings remain within specification, go to next step. If resistance readings are not within specification, go to step  7 .
    TFT SENSOR TEMPERATURE/RESISTANCE

    Temperature °F (°C) k/ohms
    -40 To -4 (-40 To -20) 284-967
    -3 To 31 (-19 To -1) 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) .5-.8

  6. Check TFT Sensor/Harness For Short To Ground

    Check continuity between BAT (-) tester jack and TFT sensor jacks. If continuity exists, go to next step. If continuity does not exist, replace PCM. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Road test vehicle. Repeat QUICK TEST  under DIAGNOSIS & TESTING. If DTC is still present, go to next step.

  7. Internal Electronic Diagnostics

    Drain transaxle fluid. Remove transaxle side cover. Inspect internal harness connector at TFT sensor. Ensure all connectors are fully connected and not damaged. Repair as needed. Install all components in reverse order of disassembly. Fill transaxle with fluid. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Repeat QUICK TEST  under DIAGNOSIS & TESTING. If all connectors are okay, go to next step.

  8. Check Internal Harness Continuity

    Disconnect internal harness from TFT sensor. Connect positive lead of ohmmeter to tester TFT (+) jack and negative lead to TFT sensor connector Black wire. Measure and record resistance. Connect positive lead of ohmmeter to tester TFT (-) jack and negative lead to TFT sensor connector White wire. If resistances measured are .5 ohm or less, go to next step. If any resistance measured is more than .5 ohm, replace internal harness. Go to step  10 .

  9. Check Internal Harness For Shorts To Ground

    Using transmission tester, check continuity between each TFT sensor connector terminal and BAT (-) terminal of tester. If continuity does not exist in any circuit, go to next step. If continuity exists in any circuit, replace internal harness. Go to next step.

  10. Check TFT Sensor Resistance

    Using ohmmeter, measure resistance between TFT sensor terminals. See TFT SENSOR TEMPERATURE/RESISTANCE  table. If resistance readings are within specification for specific temperature, go to next step. If resistance readings are not within specification, replace TFT sensor. Install all components in reverse order of disassembly. Fill transaxle with fluid. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Repeat QUICK TEST  under DIAGNOSIS & TESTING.

  11. Check TFT Sensor For Short To Ground

    Using ohmmeter, check continuity between each TFT sensor terminal and ground. If continuity exists, replace faulty TFT sensor. If continuity does not exist, install all components in reverse order of disassembly. Fill transaxle with fluid. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. Repeat QUICK TEST  under DIAGNOSIS & TESTING. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE to diagnose vehicle harness or PCM malfunctions.
scientia non olet · About LEMON Manuals