Pinpoint Test B: TFT Sensor

WARNING: This page is about a different car, the 2010 Ford Pickup, 2010 Ford F550 Super Duty, 2010 Ford F450 Super Duty, and 2010 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to the Transmission Vehicle Harness Connector illustration within the TRANSMISSION CONNECTOR LAYOUTS procedure.

NOTE: Refer to the Internal Harness Connector illustration within the TRANSMISSION CONNECTOR LAYOUTS procedure.

NOTE: Read and record all DTCs.

NOTE: Use the PID Chart for available diagnostic PIDs. Refer to DIAGNOSTIC PARAMETERS IDENTIFICATION (PID) CHART .

B1 ELECTRONIC DIAGNOSTICS
- Select PARK.
- Ignition OFF.
- Check to make sure the transmission vehicle harness C1385 is fully seated, terminals are fully engaged in the connector and are in good condition before proceeding.
- Connect the scan tool.
- Ignition ON.
- Access the Transmission Fluid Temperature (TFT) PID.
- Can the PIDs be monitored?
- Yes: GO to B2 .
- No: REPEAT procedure to access the transmission PIDs. If the scan tool did not access the transmission PIDs, REFER to the INTRODUCTION - GASOLINE MODELS or INTRODUCTION - 6.4L DIESEL - F250-F550 SUPER DUTY for diagnosis of the PCM.
B2 WARM-UP/COOL-DOWN CYCLE
- While monitoring the TFT PID, carry out the following test: If transmission is cold, warm the transmission up. If transmission is warm, allow transmission to cool down.
- Does the TFT PID 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: CLEAR the 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 Vehicle Harness C1385.
- Visually inspect all wires and connector for damage.
- Measure the voltage between the transmission vehicle harness C1385-18, harness side and ground.
  
  Fig 1: Measuring Voltage Between Transmission Vehicle Harness C1385-18, Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is voltage between 4.5 and 5.5 volts?
- Yes: GO to B4 .
- No: REPAIR an open or short in the transmission vehicle harness. CLEAR the DTCs. 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 the transmission internal harness C1385-18 and C1385-22, component side.

Fig 2: Measuring Resistance Between Transmission Internal Harness C1385-18 And C1385-22, Component Side
Courtesy of FORD MOTOR CO.
Record the resistance.

Resistance should be within specification using the following chart.

TFT

RESISTANCE REFERENCE

°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 resistance within specification?

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.

Measure the resistance between the transmission internal harness and C1385-22 and the TFT sensor connector using the following chart.

RESISTANCE REFERENCE

Transmission Connector	TFT Terminal
C1385-18	1
C1385-22	2

Is resistance less than 5 ohms?

Yes: GO to B6 .
No: INSTALL a new internal harness. CLEAR the DTCs. TEST the system for normal operation.

B6 CHECK THE INTERNAL HARNESS FOR A SHORT TO GROUND

Measure the resistance between transmission internal harness C1385 and ground using the following chart.

RESISTANCE REFERENCE

Transmission Connector	Ground
C1385-18	Ground
C1385-22	Ground

Fig 3: Measuring Resistance Between Transmission Internal Harness C1385 And Ground

Courtesy of FORD MOTOR CO.

Is resistance greater than 10,000 ohms?

Yes: GO to B7 .
No: INSTALL a new internal harness. CLEAR the DTCs. TEST the system for normal operation.

B7 CHECK THE RESISTANCE AT THE SENSOR

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

TFT

RESISTANCE REFERENCE

°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 resistance within specification?

Yes: CLEAR the DTCs. If the DTCs return and an overtemp condition is present, REFER to the INTRODUCTION - GASOLINE MODELS or INTRODUCTION - 6.4L DIESEL - F250-F550 SUPER DUTY . If the condition returns, INSTALL a new PCM.
No: INSTALL a new TFT sensor. CLEAR the DTCs. TEST the system for normal operation.