Pinpoint Test B : TFT (Transmission Fluid Temperature) Sensor
- Refer to Transmission Controls - 6R80
for schematic and connector information.
Normal Operation and Fault Conditions
The TFT sensor is a temperature dependent resistor that is in contact with transmission fluid in the transmission sump area. The PCM monitors the voltage across the TFT sensor, which changes as transmission fluid temperature varies. The PCM uses the TFT sensor signal as an input for its strategy for shifting and TCC operation. The PCM also uses the TFT sensor signal for transmission fault detection and diagnostics.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P0710:00 Transmission Fluid Temperature Sensor "A" Circuit: No Sub Type Information This DTC sets relationally if DTCs P0712 or P0713 are set, resolve these DTCs first. PCM P0711:00 Transmission Fluid Temperature Sensor "A" Circuit Range/Performance: No Sub Type Information This DTC sets when the PCM detects no change in the TFT sensor when the vehicle was driven enough that the TFT should have changed. PCM P0712:00 Transmission Fluid Temperature Sensor "A" Circuit Low: No Sub Type Information This DTC sets when the PCM detects a short to ground in the TFT sensor circuit. PCM P0713:00 Transmission Fluid Temperature Sensor "A" Circuit High: No Sub Type Information This DTC sets when the PCM detects an open in the TFT sensor circuit. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- TFT sensor
- Transmission internal wiring harness molded leadframe
- PCM
- B1 CHECK THE TFT INPUT SIGNAL
- Ignition OFF.
- Disconnect: Transmission Vehicle Harness C1575.
- Inspect the connector for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.
- Connect the diagnostic tool.
- Ignition ON.
- Using a diagnostic scan tool, access the PCM and monitor parameter identifications (PIDs) TFT and TFTV.
Does the TFTPID display -40°C (-40°F) and the TFTV PID display 4.96 to 5.10 volts?
Yes GO to B2 No GO to B3 - B2 CHECK THE TFT SIGNAL RETURN
Does the TFTPID display 190°-195°C (374°-383°F) and the TFTV PID display 0 volts?
Yes GO to B7 No GO to B3 - B3 CHECK THE TFT SIGNAL INPUT CIRCUIT FOR VOLTAGE
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1575-6 Ground
Is the voltage between 4.8 and 5.1 volts?
Yes GO to B6 No GO to B4 - B4 CHECK THE TFT SIGNAL INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect PCM C1551T.
Is the resistance less than 3 ohms?
Yes GO to B5 No REPAIR the circuit. - B5 CHECK THE TFT SIGNAL INPUT CIRCUIT FOR A SHORT TO GROUND
- Measure:
Positive Lead Measurement / Action Negative Lead C1575-6 Ground
Is the resistance greater than 10, 000 ohms?
Yes Refer to PCM Guided Routine Testing . After installing a new PCM, CARRY OUT the transmission strategy download. REFER to: Transmission Strategy Download . No REPAIR the circuit. - Measure:
- B6 CHECK THE TFT SIGNAL RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect PCM C1551T.
Is the resistance less than 3 ohms?
Yes Refer to PCM Guided Routine Testing . After installing a new PCM, CARRY OUT the transmission strategy download. REFER to: Transmission Strategy Download . No REPAIR the circuit. - B7 CHECK TFT SENSOR RESISTANCE
- Measure: (Component side using the following temperature to resistance chart)
Positive Lead Measurement / Action Negative Lead Component side, pin 5 Component side, pin 6 C1575-5 C1575-6 °C °F Resistance -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
Does the temperature to resistance specification match?
Yes The TFT sensor is operating properly at this time. To diagnose an overheating concern. REFER to: Transmission Cooling . No INSTALL a new molded leadframe, REFER to: Shift Solenoids (SS) . - Measure: (Component side using the following temperature to resistance chart)