Pinpoint Test B: TFT Sensor
Pinpoint Tests - OSC Equipped Vehicle
PINPOINT TEST B: TFT SENSOR
NOTE: Refer to the Transaxle Main Valve Body Vehicle Harness Connector illustration Transaxle Connector Layouts Transaxle Connector Layouts.
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B1 ELECTRONIC DIAGNOSTIC SETUP
- Ignition OFF.
- Select PARK.
- Check to make sure the transaxle main valve body vehicle harness C1534 is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger Mode.
- Select the TFT PID to monitor.
- Does the vehicle enter DataLogger Mode?
Yes
REMAIN in DataLogger Mode. GO to B2 .
No
REPEAT procedure to enter DataLogger Mode. If vehicle did not enter DataLogger Mode, REFER to Computers and Control Systems Information for diagnosis of PCM.
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B2 WARM-UP/COOL-DOWN CYCLE VERIFICATION
- While monitoring the TFT PID, carry out the following test: If transaxle is cold, run transaxle to warm it up. If transaxle is warm, allow transaxle to cool down.
- Does the TFT PID increase as the transaxle is warmed up or decrease as the transaxle is cooled or does the TFT PID drop in and out of range?
Yes
If the TFT PID increase as the transaxle is warmed or decrease as the transaxle is cooled, CLEAR all DTCs. ROAD TEST to verify if concern is still present. If concern is still present, REFER to Diagnosis By Symptom Diagnosis By Symptom to diagnose transaxle overheating. If the TFT drops in and out of range, INSPECT for intermittent concern in the internal/external harness, sensor or connector.
No
GO to B3.
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B3 CHECK THE MAIN VALVE BODY VEHICLE WIRING HARNESS FOR A SHORT TO POWER
- Ignition OFF.
- Disconnect: Transaxle Main Valve Body Vehicle Harness C1534.
- Disconnect: Transmission Control Module (TCM) C2352b.
- Visually inspect all wires and connectors for damage.
- Ignition ON.
- Measure the voltage between transaxle main valve body vehicle harness C1534-4, circuit VET28 (GY/VT), harness side and ground.
- Measure the voltage between transaxle main valve body vehicle harness C1534-5, circuit VET27 (BN/YE), harness side and ground.
- Is the voltage greater than 4 volts?
Yes
REPAIR the circuit for a short to power. TEST the system for normal operation.
No
GO to B4.
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B4 CHECK THE TRANSAXLE MAIN VALVE BODY VEHICLE HARNESS FOR A SHORT TO GROUND
- Disconnect: Transmission Range (TR) sensor C1537.
- Disconnect: Intermediate Shaft Speed sensor C1088.
- Measure the resistance between transaxle main valve body vehicle harness C1534-4, circuit VET28 (GY/VT), harness side and ground.
- Measure the resistance between transaxle main valve body vehicle harness C1534-5, circuit VET27 (BN/YE), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to B5.
No
REPAIR the circuit for a short to ground. TEST the system for normal operation.
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B5 CHECK THE TRANSAXLE MAIN VALVE BODY VEHICLE HARNESS FOR AN OPEN
- Measure the resistance between transaxle main valve body vehicle harness C1534-5, circuit VET27 (BN/YE), harness side and TCM C2352B-6, circuit VET27 (BN/YE).
- Measure the resistance between transaxle main valve body vehicle harness C1534-4, circuit VET28 (GY/VT), and TCM C2352B-5, circuit VET28 (GY/VT).
- Are the resistances less than 5 ohms?
Yes
GO to B6.
No
REPAIR the circuit. TEST the system for normal operation.
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B6 CHECK THE TRANSAXLE MAIN VALVE BODY INTERNAL HARNESS FOR A SHORT TO GROUND
- Measure the resistance between transaxle main valve body internal harness C1534-5 and ground.
- Measure the resistance between transaxle main valve body internal harness C1534-4 and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to B7.
No
INSTALL a new transaxle main valve body internal harness. TEST the system for normal operation.
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B7 CHECK RESISTANCE OF THE TFT SENSOR
- NOTE: Allow the engine to run long enough to reach normal operating temperature.
- TEST 1: With the transaxle at normal operating temperature, measure the resistance between transaxle main valve body internal harness C1534-5, component side and C1534-4, component side.
- Record the resistance.
- Resistance should be approximately in the following ranges:
- 10°C (50°F) - 5.587K-7.303K ohms
- 25°C (77°F) - 2.5K-4.5K ohms
- 110°C (230°F) - 0.22K-0.27K ohms
- TEST 2:Check for intermittent short or open.
- If the resistance was within range, carry out the following test. Allow the transaxle to cool. Check the Transmission Fluid Temperature (TFT) sensor resistance again. Compare the resistance with the initial resistance. The resistance should increase as the transaxle cools. If correct, then change in the resistance occurs, repeat On-Board Diagnostic (OBD).
- Are the resistances in the range?
Yes
INSTALL a new TCM. For additional information, REFER to Transmission Control Module (TCM) FNR5 - Automatic Transaxle/Transmission. TEST the system for normal operation.
No
INSTALL a new transaxle internal harness. TEST the system for normal operation.
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