P2742 Fault Code

Transmission Fluid Temperature Sensor B Circuit Low

• What does that mean?
• Symptoms
• Causes
• Solutions

The Transmission Fluid Temperature Sensor B Circuit Low fault code (P2742) indicates that the voltage from the Transmission Fluid Temperature Sensor is below the expected range. This sensor plays a critical role in monitoring the temperature of the transmission fluid, which is essential for the proper operation of the transmission.

• The sensor helps ensure that the transmission operates efficiently and avoids overheating.
• A low voltage reading can lead to improper transmission shifting and may cause damage over time.

What are the symptoms of the P2742 code?

Drivers experiencing this fault code may notice several symptoms:

• Erratic or harsh shifts when changing gears.
• Transmission overheating, which can trigger the check engine light.
• Decreased fuel efficiency as the transmission may not operate optimally.
• The possibility of the vehicle entering 'limp mode' to protect the transmission from damage, leading to reduced power and performance.

What causes the P2742 code?

There are several potential causes for this fault code, including:

• A faulty Transmission Fluid Temperature Sensor.
• Wiring issues such as frayed or shorted wires that connect the sensor to the vehicle's engine control module (ECM).
• Poor electrical connections or corroded terminals, which can disrupt the signal being sent to the ECM.
• Low transmission fluid levels, which may result in inadequate lubrication and cooling, affecting sensor performance.

How to fix P2742?

To resolve a P2742 fault code, the following steps should be taken:

• Begin with a thorough diagnostic check to confirm the fault code and assess the condition of the Transmission Fluid Temperature Sensor.
• Inspect the wiring and connectors associated with the sensor for signs of damage or corrosion; repair or replace them as necessary.
• If the sensor is found to be faulty, replace it with a new part to restore proper function.
• Ensure that the transmission fluid is filled to the correct level and is in good condition.
• After repairs, clear the fault codes and take the vehicle for a test drive to ensure that the problem is resolved.