The Automatic Transmission Fluid Temperature Sensor (TFT) Sensor is a thermistor that controls the signal voltage to the Powertrain Control Module (PCM). The PCM supplies a 5-volt reference to the sensor on circuit 1227. When the transmission fluid is cold, the sensor resistance is high and the PCM senses high signal voltage. As the fluid temperature warms to a normal transmission operating temperature, the TFT Sensor resistance becomes less and the voltage decreases.
If the PCM detects a high TFT for a long period of time, then DTC P0218 sets. DTC P0218 is a type D DTC.
• | No TFT Sensor DTCs P0712 or P0713 |
• | The TFT is greater than 135°C (275°F). |
• | All conditions are met for 410 seconds. |
• | The PCM freezes shift adapts from being updated. |
• | The PCM does not illuminate the Malfunction Indicator Lamp (MIL). |
• | Inspect the cooing system's fluid level and condition. |
• | Inspect the transmission cooler and cooler lines for damage and restrictions. |
• | The scan tool Trans. Fluid Temp. should rise steadily then stabilize. |
• | Inspect for a possible torque converter stator problem. |
• | Verify the customer's driving habits, such as trailer towing, etc . . . |
• | First diagnose and clear any engine DTCs that are present. Then inspect for any transmission DTCs that may have reset. |
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 |
Refer to Transmission Fluid Check . Did you perform the inspections? | -- | Go to Transmission Fluid Check | |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Is the TFT Sensor signal voltage less than the specified value? | 0.20 volts | Go to Diagnostic Aids | ||
Is the TFT sensor signal voltage greater than the specified value? | 4.92 volts | |||
5 |
Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||
6 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |
7 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
The Automatic Transmission Fluid Temperature (TFT) Sensor is a thermistor that controls the signal voltage to the Vehicle Control Module (VCM). The VCM supplies a 5-volt reference to the sensor on circuit 1227. When the transmission fluid is cold, the sensor resistance is high and the VCM senses high signal voltage. As the fluid temperature warms to a normal transmission operating temperature, the TFT Sensor resistance becomes less and the voltage decreases.
If the VCM detects a high TFT for a long period of time, then DTC P0218 sets. DTC P0218 is a type D DTC.
• | No TFT Sensor DTCs P0712 or P0713 |
• | The TFT is greater than 135°C (277°F). |
• | All conditions are met for 410 seconds. |
• | The VCM freezes shift adapts from being updated. |
• | The VCM does not illuminate the Malfunction Indicator Lamp (MIL). |
• | Inspect the cooling system fluid level and condition. |
• | Inspect the transmission cooler and the transmission cooler lines for damage or restrictions. |
• | The scan tool Trans. Fluid Temp. (TFT) should rise steadily then stabilize. |
• | Inspect for a possible torque converter stator problem. |
• | Verify the customer's driving habits, such as trailer towing, etc . . . |
• | First diagnose and clear any engine DTCs or TP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset. |
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 |
Refer to Transmission Fluid Check . Did you perform the inspections? | -- | Perform the inspections | |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Is the TFT Sensor signal voltage less than the specified value? | 0.20 volts | Go to Diagnostic Aids | ||
Is the TFT Sensor signal voltage greater than the specified value? | 4.92 volts | |||
5 |
Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||
6 | Replace the VCM. Refer to VCM Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |
7 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |