Fault code P2765 is called “Input/Turbine Speed Sensor “B” Circuit Malfunction” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P2765
This Diagnostic Trouble Code (DTC) is a generic powertrain code. Error P2765 is considered a generic code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly from model to model.
Fault code P2765 is displayed when the Powertrain Control Module (PCM) detects a fault in the circuit for the turbine speed sensor, known as “B”. The “B” designation is usually reserved for vehicles equipped with OBD-II that use multiple input or turbine speed sensors.
The turbine input speed sensor is usually an electromagnetic three-wire sensor. Used to monitor the input transmission speed (recognized by the PCM as rpm).
The sensor is located near the rear of the torque converter (on the transmission input shaft). It is either mounted with a bolt or screwed directly into the transmission crankcase.
There are special grooves on the transmission mainshaft that run close to the end of the sensor. When the grooves pass the transducer, the circuit is interrupted and an electronic pulse is generated. This pulse, is received by the PCM as a waveform pattern, which it recognizes as the turbine speed input.
The turbine speed input is compared to the engine speed, engine load percentage, and transmission output speed. This is done to determine the desired rpm input speed. If the actual speed does not match the desired speed, code P2765 will be stored and the “Check Engine” malfunction light will illuminate.
Symptoms of vehicle malfunctions
The main signal that an error P2765 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine control lamp on the control panel will light up (the code will be recorded in the ECM memory as a malfunction).
- Fluctuating speedometer or odometer readings.
- Hard or unstable gear shifting.
- Failure of automatic transmission to shift.
- Increased fuel consumption.
- Floating engine revolutions, as well as attempts to stall.
- Stalling of the engine while idling.
- Ignition skips in the engine cylinders may occur. Also, the car’s engine may run erratically.
In some cases, when this code is present, the PCM puts the transmission into “emergency operation mode”. In this mode, the transmission begins to operate with limitations. If the transmission begins to shift irregularly when P2765 is reported, the problem with the error should be corrected immediately.
Factors that can cause this error code
The error code P2765 can mean that one or more of the following problems have occurred:
- Damaged wiring or connectors.
- Defective input speed sensor “B”.
- Faulty output speed sensor “B”.
- Faulty shift solenoid valve.
- Contamination of ATF transmission fluid.
- Low level of transmission fluid.
- PCM failure or PCM programming error.
How to fix or reset OBD-2 code P2765
Some suggested steps for troubleshooting and fix the error code P2765:
- Connect an OBD-II scanner to the vehicle and read any error codes present.
- Clear the codes and test-drive the vehicle to see if there is a problem.
- Check the level and condition of the transmission fluid. If the level is low, refill the fluid. When the fluid is contaminated, replace it.
- If the error code does not disappear, check the transmission input speed sensor reference voltage and ground signal. Also check sensor circuit continuity and resistance.
- Repair or replace any damaged wires or circuits. If circuits and wires are OK, check all related sensors and solenoid valves.
Diagnose and repair of problems
Check error code P2765 in the maintenance bulletins (TSB) for your vehicle. Your problem may have a fix issued by the manufacturer, which may save time and money during diagnosis.
Start your diagnostics by visually inspecting the system wiring and connectors. Damaged wiring as well as connectors should be repaired or replaced. Don’t forget to check the battery and inspect the cables connected to it, also check the alternator power.
Connect the scanner to the diagnostic port, retrieve any stored codes for later use. If input and output sensor codes are present, determine which circuit is faulty.
Make sure there is no excessive metal debris on the magnetic surfaces of the sensors. For best results, remove excessive debris before reinstalling. After removing the sensors, also inspect the grooves and notches on the transmission shaft.
Use a multimeter to test the individual sensors according to the manufacturer’s specifications. Sensors that do not meet the specifications must be replaced.
Before testing resistance and continuity with a multimeter, disconnect the appropriate controllers. Failure to do so may result in controller failure.
Note a faulty PCM or PCM programming error. If all system circuits and sensors are in proper working order and meet manufacturer’s specifications.
On which vehicles does this problem occur most frequently
Fault code P2765 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- BMW
- Ford
- Honda
- Mazda
- Mercedes-Benz
- Nissan (Altima, Juke, Sentra)
- Volkswagen (Jetta)
Fault code P2765 can sometimes be found with other errors. The most common are the following: P0019, P0160, P0504, P0700, P0715, P0716, P0717, P0722, P0733, P0740, P0842, P2207.
