P2766 Input/Turbine Speed Sensor “B” Circuit Range/Performance
OBD-II Trouble Code Technical Description
Input/Turbine Speed Sensor "B" Circuit Range/Performance
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to all 1996-newer vehicles (Ford, Honda, Mazda, Mercedes, VW, etc.). Although generic, the specific repair steps may vary depending on make/model.
When a diagnostic trouble code P2766 is exhibited, it is due to the powertrain control module (PCM) detecting a malfunction in the circuit for the designated input (or turbine) speed sensor known as "B". Although input and turbine speed sensors are virtually identical in design, some manufacturers choose to vary component terminology. The A designation is typically reserved for OBD-II equipped vehicles that use multiple input or turbine speed sensors.
The input/turbine speed sensor is usually an electromagnetic, 3-wire sensor used to monitor transmission input speed (recognized by the PCM as revolutions per minute or RPMs). The sensor is positioned near the rear of the torque converter (at the transmission input shaft) and is either mounted with a bolt/stud or threaded directly into the transmission case.
On the transmission main (or input) shaft, specially designed grooves (or a notched reluctor wheel) are present. The input shaft (or reluctor wheel) passes in close proximity to the end of the sensor; completing the electromagnetic circuit. As the grooves (or notches) pass by the sensor, the circuit is interrupted and an electronic pattern is formed. This pattern formation is received by the PCM as a waveform pattern that it further interprets as transmission input/turbine speed.
Transmission input/turbine speed is compared with engine RPM speed, percentage of engine load, and transmission output speed to determine the desired input speed RPM. If the actual input/turbine speed fails to coincide with the desired input/turbine speed, a code will be stored and a malfunction lamp may be illuminated.
Symptoms & Severity
In some instances, the PCM will place the transmission in ‘limp-in’ mode when this code is stored. The transmission will shift harshly in this mode. If the transmission begins to shift irregularly when you are presented with a P2766, the problem should be addressed immediately.
Symptoms of a P2766 code may include:
Causes
Potential causes for this code to set are:
Diagnostic and Repair Procedures
A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis.
An advanced diagnostic scanner, a digital volt/ohmmeter (DVOM), a manufacturer’s service manual, and possibly an oscilloscope will be helpful in diagnosing the P2766 code.
I would likely begin my diagnosis with a visual inspection of system wiring and connectors. Disconnected, corroded, burnt, or shorted wiring and/or connectors must be repaired or replaced. Don’t forget to test the battery and inspect battery cables and cable ends. Test alternator output as well.
I make it a habit to connect the scanner to the diagnostic port and retrieve all stored codes and write them down for future reference. I also like to make a note of the freeze frame data.
If input sensor and output sensor codes are present, use the scanner data stream to determine which circuit is at fault. For more accurate data, narrow the data stream to include only pertinent information.
Check for excessive metal debris on magnetic surfaces of input and/or output speed sensors. For best results, remove excessive debris before reinstallation. When sensors are removed, inspect interruption grooves and/or reluctor wheel notches, as well.
Use the DVOM to test individual sensors, following manufacturer’s specifications (found in the service manual or through All Data). Sensors that do not comply with manufacturer’s specifications must be replaced. Some manufacturers recommend replacement of input and output speed sensors as a set. Before testing resistance and continuity with the DVOM, disconnect related controllers. Failure to do so could result in controller failure.
Suspect a faulty PCM or a PCM programming error if all system circuits and sensors are in proper working order and comply with manufacturer’s specifications.
Additional diagnostic notes:
Need help?
Let us fix your problem. You are most welcome our diagnosis experts have in most cases the knowledge and skills to find the cause of the error code p2766 and to solve the problems.
Make an appointment for diagnosis
"Delete Error Code Permanently, Disable DTC Error Code Function for p2766 in the ECU"
In extreme cases, we even have the option to permanently remove the specific DTC p2766 and disable the function of the specific error code in the ECU. All other fault code functions will then continue to work to protect the engine. This is different from clearing an error code with a diagnostic device. We have the option to permanently remove the function of the specific error code, so that it never comes back. Also emergency running that occurs on the specific error code can be solved in most cases.
Of course we prefer to first try to solve the cause of the error code, but sometimes the only solution is to permanently disable the DTC function of p2766.
