Transmission Fluid Temperature Sensor Circuit Malfunction
The P2740 code indicates a problem in the transmission fluid temperature (TFT) sensor circuit. This sensor monitors the temperature of the transmission fluid and sends a signal to the powertrain control module (PCM). The PCM uses this data to adjust shift patterns, torque converter lockup, and line pressure. A circuit malfunction can be due to a faulty sensor, damaged wiring, or poor electrical connections. If the PCM detects an out-of-range or implausible signal, it sets this code.
01. Most Common Causes
- Faulty transmission fluid temperature sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Low or contaminated transmission fluid
- Internal transmission failure causing abnormal temperatures
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or overheating
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Inspect the TFT sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Measure the resistance of the TFT sensor and compare to manufacturer specifications (typically varies with temperature).
Step 4: Check transmission fluid level and condition; top off or replace if necessary.
Step 5: If sensor and wiring are okay, test the circuit at the PCM connector for continuity and voltage.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the transmission may shift improperly or overheat, leading to internal damage. Limited local driving may be possible, but have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $150 to $300, including parts and labor. A new TFT sensor costs $30-$80, and labor is 1-2 hours. Additional costs may apply if wiring repairs or fluid replacement is needed.