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P2741 — Transmission Fluid Temperature Sensor B Circuit Rangeperformance

Manufacturer-specificPowertrain (engine & transmission)

P2741 indicates the transmission control module has detected an irrational or out-of-range signal from the transmission fluid temperature sensor B. This sensor monitors fluid temperature to optimize shift quality and protect the transmission from overheating. The code sets when the sensor voltage or resistance falls outside calibrated limits or does not change as expected during operation.

Symptoms

What causes it — most likely first

1. Failed transmission fluid temperature sensor B

The sensor element itself has degraded or failed, producing a signal that does not correspond to actual fluid temperature.

2. Damaged wiring or connector in sensor B circuit

Chafed, cut, or pinched wires, or a damaged connector, create an open or high-resistance path that skews the sensor signal.

3. Short to voltage or ground in sensor B signal circuit

A short circuit pulls the sensor signal voltage high or low, causing the TCM to read an impossible temperature value.

4. Corroded or loose sensor B connector

Corrosion or a loose terminal adds resistance or intermittent contact, leading to erratic or out-of-range readings.

5. Faulty transmission control module (TCM)

Internal TCM circuitry that processes the sensor signal may be damaged, though this is less common than sensor or wiring faults.

6. PCM/ECM failure (rare, only if TCM integrated and other codes present)

On vehicles where the TCM is integrated into the PCM, a module failure could cause this code, but it is the least likely cause and should be considered only after all other possibilities are eliminated.

How it's diagnosed

  1. Scan for additional transmission codes and freeze frame data to identify related issues.
  2. Visually inspect sensor B wiring harness and connector for damage, corrosion, or loose terminals.
  3. Test sensor B resistance at various temperatures using a multimeter and compare readings to manufacturer specifications.
  4. Check sensor B signal voltage and ground at the TCM connector with the ignition on and engine running.
  5. Perform a wiggle test on the harness while monitoring live sensor data for fluctuations indicating an intermittent fault.
  6. If wiring and sensor test within specifications, evaluate TCM/PCM operation with advanced diagnostic equipment before considering module replacement.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Can I drive with P2741?

Not recommended; the transmission may enter limp mode, shift harshly, or overheat due to incorrect temperature data.

Is P2741 caused by a bad PCM?

Rarely; the sensor or its wiring is the most common cause. PCM replacement is almost never the correct fix unless all other possibilities are eliminated.

Does this code affect fuel economy?

Yes, incorrect fluid temperature data can prevent torque converter lockup and cause inefficient shift scheduling, reducing fuel economy.

Can a transmission fluid change fix P2741?

Only if the sensor is contaminated by debris; a fluid change alone will not repair a faulty sensor or wiring issue.