P2768 OBD-II Problem Code: Input/Turbine Speed Sensor B Circuit Intermediate

P2768 code definition

The P2768 code is stored when the powertrain control module (PCM) receives an input signal from the turbine speed sensor that is in erratic, irrational, or in some other way incorrect or unusable. Without the proper signal from the turbine speed sensor, the transmission is unable to provide a working shift strategy. In the case of P2768, a car with multiple sensors will have an intermittent malfunction in Sensor B.

What the P2768 code means

The PCM “expects” the input speed from the turbine speed sensor to increase gradually until it reaches a shift point, at which time the transmission will shift. A varying, erratic, or irrational signal (or a complete lack of signal) will cause the P2768 code to be stored, as the transmission will be unable to determine when or how to shift, and a Malfunction Indicator Light (MIL) will be illuminated.

What causes the P2768 code?

There are a few things that commonly cause a P2768 code to be stored, including:

• A defective input speed sensor
• A defective output speed sensor
• Defective engine drivability sensors
• Open or shorted wiring circuits
• Corroded or otherwise damaged wiring circuits and/or connectors
• Faulty solenoid(s)
• Contaminated or dirty transmission fluid
• A defective valve body
• A fault with the PCM (rare)

What are the symptoms of the P2768 code?

The first and most noticeable symptoms that a driver will detect include:

• Hard shifting
• Failure to shift
• Lowered fuel efficiency
• Fluctuating speeds on the speedometer (or failure to indicate speed)
• Stalling when the vehicle comes to a stop
• Misfiring engine
• Hesitation upon acceleration

In all cases a Check Engine Light or MIL will illuminate, and in some rare cases this will be the only symptom.

How does a mechanic diagnose the P2768 code?

A mechanic diagnosing a P2768 code will use a scanner to detect other related codes. They will also inspect the wiring and circuits that connect the turbine speed sensor and look for transmission fluid leaks, which may have caused the problem to occur. After all codes are cleared, the mechanic will operate the vehicle to ensure that the codes remain clear and that the problem has been addressed.

Common mistakes when diagnosing the P2768 code

The most common mistakes made when diagnosing a P2768 code include misdiagnosing the problem as:

• An internal transmission issue
• A vehicle speed malfunction
• A fuel delivery issue
• An engine misfire
• A driveline malfunction

Often, this results in unnecessarily replacing the vehicle speed sensor, which will not actually fix the problem at hand.

How serious is the P2768 code?

If a vehicle’s automatic transmission is not able to provide the proper shifting strategy while driving, the vehicle may stall at inopportune times, lose fuel efficiency, be unable to shift, and other problems may occur. Depending on the situation, these problems can be very serious. The driver may be put in danger, and the vehicle’s transmission and other systems may be further damaged, as well.

What repairs can fix the P2768 code?

• Replace or repair the corroded or damaged wiring that is causing the signal to be intermittent.

In some rare cases, the vehicle’s PCM may need to be repaired or replaced.

Additional comments for consideration regarding the P2768 code

Failing to resolve the P2768 code can be detrimental to the vehicle and can put the driver in danger. Not only that, but if the P2768 code is still stored, the Check Engine Light will remain illuminated, and the vehicle may not pass an OBD-II emissions test. Thus, it is essential to have a professional mechanic diagnose and repair the problem so that the code is resolved and the vehicle is safe to drive once more.

Need help with a P2768 code?

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