Transmission Fluid Temperature Sensor "B" Circuit Intermittent
P2744 indicates an intermittent circuit fault with the transmission fluid temperature sensor B, which monitors transmission fluid temperature to optimize shift timing and torque converter clutch operation. The PCM detects inconsistent or erratic voltage signals from the sensor, causing improper transmission behavior.
What You Might Notice
- Check engine light illuminated
- Harsh or delayed transmission shifts
- Improper torque converter clutch operation
- Transmission slipping or hunting between gears
- Reduced fuel economy
Most Common Causes
- 1
Faulty transmission fluid temperature sensor
The sensor contacts may be corroded, the sensor element may be failing intermittently, or internal resistance may be fluctuating causing inconsistent signals to the PCM.
- 2
Wiring or connector problems
Corroded, loose, or damaged wiring connections between the sensor and PCM, or a faulty connector creating intermittent contact that causes signal loss.
- 3
Transmission fluid contamination or low level
Contaminated or low transmission fluid can affect sensor accuracy and create electrical issues in the sensor circuit.
- 4
Faulty PCM or transmission control module
In rare cases, the PCM or transmission control module itself may have a faulty input circuit causing it to misinterpret valid sensor signals.
How to Diagnose It
- 1
Check Faulty transmission fluid temperature sensor — The sensor contacts may be corroded, the sensor element may be failing intermittently, or internal resistance may be fluctuating causing inconsistent signals to the PCM.
- 2
Check Wiring or connector problems — Corroded, loose, or damaged wiring connections between the sensor and PCM, or a faulty connector creating intermittent contact that causes signal loss.
- 3
Check Transmission fluid contamination or low level — Contaminated or low transmission fluid can affect sensor accuracy and create electrical issues in the sensor circuit.
- 4
Check Faulty PCM or transmission control module — In rare cases, the PCM or transmission control module itself may have a faulty input circuit causing it to misinterpret valid sensor signals.
How to Fix It
- 1
Inspect and repair sensor wiring and connectors
Check the transmission fluid temperature sensor B connector and wiring harness for corrosion, damage, or loose connections. Clean connectors with electrical contact cleaner and reseat connections, or replace damaged wiring as needed.
- 2
Replace transmission fluid temperature sensor B
Remove and replace the faulty transmission fluid temperature sensor. Ensure the new sensor is properly torqued and the connector is fully seated to restore reliable temperature signal transmission to the PCM.
- 3
Check and service transmission fluid
Check transmission fluid level and condition; top up or perform a fluid change if the fluid is dark, contaminated, or below the minimum level. Clean fluid ensures proper sensor operation.
- 4
Test PCM and reprogram if necessary
If sensor and wiring are confirmed good, have the PCM tested by a professional diagnostic center. A software update or PCM replacement may be required if the module's input circuit is defective.
Need a deeper diagnosis?
Search for related repair guides or browse by system.