Pinpoint Test B : TFT (Transmission Fluid Temperature) Sensor

Pinpoint Tests - OSC Equipped Vehicle

Pinpoint Tests

PINPOINT TEST B : TFT (Transmission Fluid Temperature) SENSOR

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

B1 ELECTRONIC DIAGNOSTICS

- Check to make sure the transaxle vehicle harness 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: Transaxle Vehicle Harness C1520A.

- Disconnect: PCM Transaxle Harness C175T.

- 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 PCM transaxle harness C175T-19, circuit VET27 (BN/YE) and transaxle vehicle harness C1520A-2, circuit VET27 (BN/YE).





- Measure the resistance between PCM transaxle harness C175T-41, circuit RE406 (GY/VT) and transaxle vehicle harness C1520A-1, circuit RE406 (GY/VT).





Is the resistance less than 5 ohms?

Yes
GO to B3.

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

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

- Disconnect: Catalyst Monitor Sensor (CMS) C141.

- Disconnect: CMS (Catalyst Monitor Sensor) C142.

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





- Measure the resistance between transaxle vehicle harness C1520A-1, circuit RE406 (GY/VT) and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to B4.

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

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

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





- Measure the voltage between transaxle vehicle harness C1520A-1, circuit RE406 (GY/VT) and ground.





Is any voltage present?

Yes
REPAIR the circuit(s) for a short to voltage. 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

- Vehicle must be at normal operating temperature.

- Connect: Transaxle Vehicle Harness C1520A.

- TEST 1.

- Measure and record the resistance between PCM transaxle harness C175T-19, circuit VET27 (BN/YE) and C175T-41, circuit RE406 (GY/VT).





- Compare the resistance value to the following table ranges:

Transmission Fluid Temperature (TFT)

° 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 transaxle 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 transaxle was heated and should increase if the transaxle was allowed to cool. If correct, then change in the resistance occurs, repeat On-Board Diagnostic (OBD).

Is the resistance in range?

Yes
INSTALL a new PCM. 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.