Code Severity and Symptoms
The severity of this code is moderate to severe. In some cases, this code may indicate a transmission problem. It’s a good idea to address this code as soon as possible.
Symptoms of a P2741 engine code may include:
- Check engine light
- Poor torque converter clutch operation
- Hard or delayed shifts
- Vehicle stuck in limp mode
Causes
Causes of this fault code may include:
- Faulty transmission fluid temperature sensor
- Transmission problems
- Wiring issues
- Faulty PCM
Diagnostic and Repair Procedures
Start by visually inspecting the transmission fluid temperature sensor and its corresponding wiring. Look for loose connections, damaged wiring, etc. If damage is detected, repair as needed, clear the code, and see if it returns. Then, check technical service bulletins (TSBs) regarding the issue. If nothing is found, you’ll need to proceed with step-by-step system diagnosis.
The following is a generalized procedure, as tests for this code vary by vehicle. To accurately test the system, you’ll need to refer to the manufacturer’s diagnostic flowchart.
Perform Preliminary Circuit Tests
Use a scan tool to monitor the transmission temperature sensor data parameter. Disconnect the TFT sensor; the scan tool value should drop to a very low value. Then, connect a jumper between the terminals. If the scan tool now displays a very high temperature, the connections are solid and the ECM can recognize the input. This means the problem most likely lies with the sensor rather than a circuit or PCM issue.
Test the Sensor
Disconnect the transmission fluid temperature sensor connector. Then, measure the resistance between the two sensor terminals using a digital multimeter set to ohms. Start the engine and watch the meter value; the values should decrease smoothly as the engine warms up (check the engine temperature gauge on the dashboard to ensure the engine reaches operating temperature). If the engine temperature increases but the TFT resistance does not decrease, the sensor is faulty and needs to be replaced.
Check the Circuit
Check the reference voltage side of the circuit: ignition on, use a digital multimeter set to volts to check for a 5-volt reference from the PCM to one of the two transmission fluid temperature sensor terminals. If no reference signal is present, set the meter to ohms (ignition off) between the reference voltage pin on the TFT and the reference voltage pin on the PCM. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired. If the meter reads a numerical value, there is continuity.
If everything is fine up to this point, you’ll want to verify that there are 5 volts coming from the PCM at the reference voltage terminal. If there is no 5-volt reference from the PCM, the PCM is likely faulty.
Check the Ground Side of the Circuit
Connect the meter set to ohms (ignition off) between the ground terminal of the transmission fluid temperature sensor and the ground terminal of the PCM. If the meter reads out of limits (OL), there is an open circuit between the PCM and the sensor that will need to be located and repaired. If the meter reads a numerical value, there is continuity. Finally, verify that the PCM has a good ground by attaching one meter lead to the PCM ground terminal and the other to chassis ground. Again, if the meter reads out of limits (OL), there is an open circuit between the PCM and ground that will need to be located and repaired.
If everything in the circuit checks out, there may be a problem with the transmission. This is especially true if transmission fluid temperature codes are set along with other transmission codes.