Pinpoint Test B: TFT (Transmission Fluid Temperature) Sensor

Pinpoint Tests - OSC Equipped Vehicle

PINPOINT TEST B : TFT (Transmission Fluid Temperature) SENSOR

NOTE: Refer to the transmission connector illustrations and solenoid body leadframe internal wiring diagram Transaxle Connector Layouts .

B1 ELECTRONIC DIAGNOSTICS

- Check to make sure the C1520A is fully seated, terminals are fully engaged in connector and in good condition before proceeding.

Have the above items been checked?

Yes
GO to B2.

No
CARRY OUT checks. CLEAR the DTCs. REPEAT the self-test.

B2 CHECK THE TFT (Transmission Fluid Temperature) SENSOR CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: C1520A.

- Disconnect: TCM (Transmission Control Module) C1750.

- Use a mirror to inspect both ends of the connector for damage or pushed-out terminals, corrosion, loose wires and missing or damaged seals.

- Measure the resistance between TCM (Transmission Control Module) C1750-54, circuit VET27 (BN/YE), harness side, and C1520A-2, circuit VET27 (BN/YE), harness side.






- Measure the resistance between TCM (Transmission Control Module) C1750-46, circuit RE407 (YE/VT), harness side, and C1520A-1, circuit RE407 (YE/VT), harness side.






Is the resistance less than 5 ohms?

Yes
GO to B3.

No
REPAIR the circuit(s). CONNECT all components. TEST the system for normal operation.

B3 CHECK THE TFT (Transmission Fluid Temperature) SENSOR CIRCUITS FOR A SHORT TO GROUND

- Measure the resistance between C1520A-2, circuit VET27 (BN/YE) and ground.






- Measure the resistance between C1520A-1, circuit RE407 (YE/VT) and ground.






Is the resistance greater than 10,000 ohms?

Yes
GO to B4.

No
REPAIR the circuit(s). CONNECT all components. TEST the system for normal operation.

B4 CHECK THE TFT (Transmission Fluid Temperature) CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition ON.

- Measure the voltage between C1520A-2, circuit VET27 (BN/YE) and ground.






- Measure the voltage between C1520A-1, circuit RE407 (YE/VT) and ground.






Is any voltage present?

Yes
REPAIR the circuit(s). CONNECT all components. TEST the system for normal operation.

No
GO to B5.

B5 CHECK THE RESISTANCE OF THE TFT (Transmission Fluid Temperature) SENSORS/HARNESS

- Connect: C1520A.

- Connect: TCM (Transmission Control Module) C1750.

- Start the engine.

- Bring the transmission to normal operating temperature.

- Ignition OFF.

- TEST 1.

- Measure and record the resistance between TCM (Transmission Control Module) C1750-54, circuit VET27 (BN/YE), harness side, and TCM (Transmission Control Module) C1750-46, circuit RE407 (YE/VT), harness side.






- Compare the recorded resistance value to the following table ranges:

TFT (Transmission Fluid Temperature)

°C° F Resistance (Ohms) -40 to -20 -40 to -4 1076K-269K -19 to -1 -3 to 31 309K-91K 0-20 32-68 104K-35K 21-40 69-104 40K-15K 41-70 105-158 17K-4.9K 71-90 159-194 5.6K-2.5K 91-110 195-230 3.0K-1.4K 111-130 231-266 1.7K-0.8K 131-150 267-302 0.97K-0.56K

- TEST 2.

- Check for intermittent short or open.

- If the resistance was between 0.8K and 100K ohms carry out the following test. If the transmission is warm, allow it to cool. Check the TFT (Transmission Fluid Temperature) sensor resistance again. Compare the resistance with the initial resistance. The resistance should decrease if the transmission was heated and should increase if the transmission was allowed to cool. If correct, then change in the resistance occurs, repeat OBD (On-Board Diagnostic).

Is the resistance in range?

Yes
INSTALL a new TCM (Transmission Control Module). REFER to Transmission Control Module (TCM) . CONNECT all components. TEST the system for normal operation.

No
INSTALL a new solenoid body leadframe. REFER to Solenoid Body Leadframe . RECONNECT all components. TEST the system for normal operation.