Description of the P0737 fault code.
OBD2 Error Codes

P0737 Transmission control module (TCM) engine speed output circuit malfunction

26.05.2022 /

P0737 – OBD-II Trouble Code Technical Description

Trouble code P0737 indicates a malfunction of the engine speed output circuit in the transmission control module (TCM).

What does the fault code mean P0737?

Trouble code P0737 indicates a problem with the engine speed output circuit in the transmission control module (TCM). This means that the TCM has detected that the engine speed is outside the set range or the signal from the engine speed sensor (ESS) is not as expected.

Fault code P0737.

Possible reasons

Several possible causes for trouble code P0737:

  • Faulty Engine Speed ​​Sensor (ESS): If the engine speed sensor is faulty or damaged, it may send incorrect engine speed data to the TCM, causing P0737 to occur.
  • Problems with wiring or connectors: Damaged or broken wires or faulty connectors can cause problems with the transmission of data from the engine speed sensor to the TCM, resulting in P0737.
  • TCM malfunction: If the TCM is faulty or defective, it may misinterpret signals from the engine speed sensor, causing P0737 to occur.
  • Power circuit problems: Problems with the TCM power or ground may cause improper operation or loss of communication with the engine speed sensor, resulting in a P0737 code.
  • Malfunctions in other vehicle systems: Certain problems in other systems, such as the ignition system or engine management system, can also cause P0737 because engine speed is related to their operation.

These are just a few of the possible causes of the P0737 trouble code. To accurately determine the cause, it is recommended to have the vehicle diagnosed at a specialized car service center or a qualified mechanic.

What are the symptoms of a fault code? P0737?

Symptoms for DTC P0737 may include the following:

  • Using Emergency Mode: In some cases, the vehicle may go into limp mode or power limited mode due to a problem related to engine speed.
  • Gear shifting problems: Gear shifting may become erratic or delayed. This may manifest itself as long delays during shifting, jerking or abrupt gear changes.
  • Uneven engine operation: The engine may run rough, idle rough, or experience unusual vibrations while driving.
  • Check Engine Light Illuminates: When the P0737 trouble code appears, the Check Engine Light (check engine light) on the vehicle's instrument panel will illuminate. This may be one of the first noticeable signs of a problem.
  • Loss of power: In some cases, the vehicle may lose power due to engine management system malfunction caused by a problem related to engine speed.

These symptoms may occur to varying degrees depending on the specific problem and the type of vehicle.

How to diagnose a fault code P0737?

To diagnose DTC P0737, you can follow these steps:

  1. Scan error code: Use a vehicle scanner or diagnostic tool to scan for error code P0737. This will help you confirm the problem and get more information about it.
  2. Checking wiring and connectors: Check the wiring and connectors connecting the Engine Speed ​​Sensor (ESS) to the Transmission Control Module (TCM). Make sure the wiring is intact, undamaged and well connected.
  3. Checking the Engine Speed ​​Sensor (ESS): Check the operation of the engine speed sensor. Check its resistance and the signals generated when the motor rotates. If the sensor is not functioning properly, it may need to be replaced.
  4. Transmission Control Module (TCM) Diagnosis: Check the condition and operation of the TCM. Verify that the TCM is receiving correct signals from the engine speed sensor and is processing this data correctly. If necessary, test or replace the TCM.
  5. Checking signals from the engine speed sensor: Using a multimeter or oscilloscope, check the signals from the engine speed sensor to the TCM. Verify that the signals are as expected.
  6. Diagnostics of other related systems: Check other related systems such as the ignition system, fuel injection system, or engine management system that may be affecting the engine speed sensor.
  7. Updating the softwareNote: In some cases, updating the TCM software may help resolve the problem if it is caused by a software glitch.

After diagnosing and identifying the cause of the P0737 error, you can begin to repair or replace the faulty components. If you are unsure of your skills or experience, it is recommended that you contact a professional mechanic or auto repair shop to perform diagnostics and repairs.

Diagnostic errors


When diagnosing DTC P0737, the following errors may occur:

  1. Insufficient engine speed sensor (ESS) check: If you do not thoroughly check the engine speed sensor, you may miss potential problems with the engine speed sensor, resulting in a misdiagnosis.
  2. Ignoring other related systems: Incorrect determination of the cause of the P0737 code may be due to ignorance of other systems, such as the ignition system or engine management system, that may affect the operation of the engine speed sensor.
  3. Insufficient testing of wiring and connectors: The wiring and connectors connecting the engine speed sensor to the TCM should be checked to rule out possible connection problems or broken wiring.
  4. Faulty TCM Diagnostics: If the TCM is not checked or tested properly, problems with its operation or tuning may be missed, resulting in an incorrect diagnosis.
  5. Misinterpretation of data: Incorrect interpretation of diagnostic data may lead to an incorrect conclusion about the cause of the P0737 code and, as a result, incorrect repairs.
  6. Skipping a software update: In some cases, updating the TCM software may help resolve the problem, but if not done or taken into account, it may lead to an incorrect diagnosis.

All of these errors can lead to incorrect diagnosis and repair, so it is important to take a systematic approach to diagnosing and fixing the problem, and contact a professional if you are unsure of what to do.

How serious is the fault code? P0737?

The severity of the P0737 trouble code may vary depending on the specific circumstances and reasons for its occurrence. In general, it is important to pay attention to this code and take action to resolve it because it indicates a problem with the engine speed output circuit that can affect transmission operation and vehicle performance.

Some of the possible consequences and serious aspects associated with the P0737 code:

  • Potential loss of vehicle control: Incorrect operation of the transmission system can lead to poor vehicle handling and loss of control while driving.
  • Increased component wear: An improperly functioning transmission can cause increased wear on transmission components such as clutches, discs and pistons, which may ultimately require more expensive repairs.
  • Loss of power and efficiency: Improper gear shifting can result in loss of power and increased fuel consumption, which will negatively affect the vehicle's economy and performance.
  • Irregular symptoms: Symptoms of P0737, such as rough shifting, rough engine operation, or improper transmission operation, can cause driver and passenger discomfort and pose a hazard on the road.

Overall, although the P0737 trouble code may not pose an immediate safety threat, its severity lies in its ability to affect the normal functioning of the vehicle and set the stage for further problems. Therefore, it is important to immediately contact a professional to diagnose and fix this problem.

What repair will help eliminate the code? P0737?

Resolving the P0737 trouble code depends on the specific cause of it, some possible repair measures that may help:

  1. Replacing or servicing the Engine Speed ​​Sensor (ESS): If the engine speed sensor fails or does not function correctly, it must be replaced or serviced.
  2. Checking and servicing wiring and connectors: Check the wiring and connectors connecting the engine speed sensor to the transmission control module (TCM). Make sure the wiring is intact and connections are secure.
  3. Transmission Control Module (TCM) Diagnosis and Service: Check the condition and operation of the TCM. If it is found to be faulty, it may require repair or replacement.
  4. TCM Software Update: Sometimes updating the TCM software can help fix the problem if it is caused by a software glitch.
  5. Checking and servicing other related systems: Check other related systems, such as the ignition system or engine management system, that may be affecting the engine speed sensor.
  6. Checking and servicing the power circuit: Check the power circuit supplying power to the TCM as well as its ground. Make sure they are functioning correctly.
  7. Repair or replacement of other components: If other faults are identified that may affect the operation of the gearbox, they also need to be repaired or replaced.

After diagnosing and identifying the cause of the P0737 code, repair steps can be taken to correct the problem. It is important to contact qualified professionals to perform repair work, especially if you are unsure of your skills or experience.

How to Diagnose and Fix P0737 Engine Code - OBD II Trouble Code Explain

P0737 – Brand-specific information

Trouble code P0737 indicates a problem with the engine speed output circuit in the Transmission Control Module (TCM), for some well-known vehicle brands:

These are just a few examples, and the meaning of the P0737 code may vary slightly depending on the specific model and year of the vehicle. For more accurate information, it is recommended to consult official repair manuals or contact qualified car service technicians who specialize in this brand.

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