Pinpoint Test B: Transmission Fluid Temperature (TFT) Sensor

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to the TRANSMISSION VEHICLE HARNESS CONNECTOR illustration preceding these pinpoint tests.

NOTE: Refer to the INTERNAL HARNESS CONNECTOR illustration preceding these pinpoint tests.

NOTE: Read and record all DTCs.

NOTE: Use the PID Chart for available diagnostic PIDs. Refer to OUTPUT STATE CONTROL (OSC) MODE .

B1 ELECTRONIC DIAGNOSTICS
- Key in OFF position.
- Select PARK.
- Check to make sure the transmission harness connector is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
- Connect the scan tool.
- Key in ON position.
- Enter the following diagnostic mode on the scan tool: Monitor PIDs For TFT.
- Does the vehicle enter PID/Data Monitor and Record?
- Yes : REMAIN in PID/Data Control. GO to B2.
- No : REPEAT procedure to enter PID. If vehicle did not enter PID, see INTRODUCTION - GASOLINE and/or INTRODUCTION -- 6.0L DIESEL articles for diagnosis of powertrain control module (PCM) and VCM.
B2 WARM-UP/COOL-DOWN CYCLE
- While monitoring the TFT PIDs, carry out the following test: If transmission is cold, operate 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 drop in and out of range?
- Yes : If the TFT PIDs increase as the transmission is warmed or decrease as the transmission is cooled, CLEAR all DTCs. CARRY OUT the road test to verify if concern is still present. If concern is still present, REFER to DIAGNOSIS BY SYMPTOM to diagnose transmission overheating.
- No : GO to B3.
B3 ELECTRICAL SIGNAL CHECK
- Disconnect: Transmission Harness Connector.
- Visually inspect all wires and connectors for damage.
- Measure the voltage between pin 18 harness side and ground.
- Is the voltage between 4.5 and 5.5 volts?
- Yes : GO to B4.
- No : REPAIR an open or short in the harness. TEST the system for normal operation. If normal operation does not return, INSTALL a new PCM.

B4 CHECK THE RESISTANCE OF THE TFT SENSOR

Measure the resistance between pins 18 and 22 at the transmission bulkhead body connector.
Record the resistance.

Resistance should be approximately in the following ranges:

TRANSMISSION FLUID TEMPERATURE

°C	°F	Resistance (Ohms)
-40 to -20	-40 to -4	967K - 284K
-19 to -1	-3 to 31	284K - 100K
0 to 20	32 to 68	100K - 37K
21 to 40	69 to 104	37K - 16K
41 to 70	105 to 158	16K - 5K
71 to 90	159 to 194	5K - 2.7K
91 to 110	195 to 230	2.7K - 1.5K
111 to 130	231 to 266	1.5K - 0.8K
131 to 150	267 to 302	0.8K - 0.54K

Is the resistance in range?

Yes : REFER to DIAGNOSIS BY SYMPTOM to diagnose an overheating concern.
No : GO to B5.

B5 CHECK THE INTERNAL HARNESS FOR AN OPEN
- Drain the transmission fluid.
- Remove the transmission fluid pan.
- Disconnect: TFT Sensor Connector.
- Measure the resistance between the TFT sensor connector pin 1 and the transmission bulkhead connector pin 18.
- Measure the resistance between the TFT sensor connector pin 2 and the transmission bulkhead connector pin 22.
- Are the resistances less than 0.5 ohms?
- Yes : GO to B6.
- No : INSTALL a new harness. GO to B7.
B6 CHECK THE INTERNAL HARNESS FOR A SHORT TO GROUND
- Measure the resistance between the TFT sensor connector pins 18 and 22, and ground.
- Is the resistance greater than 10,000 ohms?
- Yes : INSTALL a new internal harness.
- No : GO to B7.

B7 CHECK THE RESISTANCE AT THE SENSOR

Measure the resistance between pins 1 and 2 at the TFT sensor.

TRANSMISSION FLUID TEMPERATURE

°C	°F	Resistance (Ohms)
-40 to -20	-40 to -4	967K - 284K
-19 to -1	-3 to 31	284K - 100K
0 to 20	32 to 68	100K - 37K
21 to 40	69 to 104	37K - 16K
41 to 70	105 to 158	16K - 5K
71 to 90	159 to 194	5K - 2.7K
91 to 110	195 to 230	2.7K - 1.5K
111 to 130	231 to 266	1.5K - 0.8K
131 to 150	267 to 302	0.8K - 0.54K

Is the resistance within specification?

Yes : GO to B8.
No : INSTALL a new TFT sensor. CLEAR the DTCs. TEST the system for normal operation.

B8 CHECK THE SENSOR FOR A SHORT TO GROUND
- Measure the resistance between pins 1 and 2 at the TFT sensor connector and ground.
- Is the resistance less than 10,000 ohms?
- Yes : INSTALL a new TFT sensor.
- No : INSTALL a new PCM. CLEAR the DTCs. If the DTCs return and an overtemp condition may exist, REFER to DIAGNOSIS BY SYMPTOM .