P1739 – OBD-II DTC

OBD-II DTC P1739 – Gear Control Malfunction

DTC P1739 meaning

DTC P1739 refers to a “Gear Control Malfunction” in the vehicle’s transmission system. This code indicates that the transmission control module (TCM) has detected an issue with the gear selection or shifting process. It may be related to the transmission’s ability to engage or disengage gears properly, which can affect the vehicle’s performance and drivability.

DTC P1739 symptoms

Common symptoms associated with DTC P1739 may include:

• Unusual or harsh shifting of gears
• Delayed engagement when shifting from park to drive or reverse
• Transmission slipping or failing to shift
• Warning lights illuminated on the dashboard, such as the check engine light
• Reduced acceleration or power loss

DTC P1739 causes

Several factors can contribute to the occurrence of DTC P1739, including:

• Faulty transmission control module (TCM)
• Wiring issues or poor connections in the transmission system
• Malfunctioning sensors, such as the vehicle speed sensor or transmission range sensor
• Low transmission fluid levels or fluid contamination
• Mechanical issues within the transmission, such as worn gears or clutches

DTC P1739 seriousness

DTC P1739 is considered a serious issue as it can lead to significant transmission problems. If left unaddressed, it may result in complete transmission failure, which can be costly to repair. Additionally, the symptoms associated with this code can affect the vehicle’s safety and drivability, making it essential to diagnose and resolve the issue promptly.

How to diagnose DTC P1739

To diagnose DTC P1739, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1739 code.
2. Check for any additional trouble codes that may provide more context.
3. Inspect the transmission fluid level and condition, looking for signs of contamination.
4. Examine the wiring and connectors related to the TCM and transmission sensors for damage or corrosion.
5. Test the operation of the transmission range sensor and vehicle speed sensor.
6. Perform a visual inspection of the transmission for any mechanical issues.

How to fix DTC P1739 step-by-step instructions

To fix DTC P1739, follow these steps:

1. Address any low or contaminated transmission fluid by replacing it and ensuring the correct level.
2. Repair or replace any damaged wiring or connectors found during the inspection.
3. Replace faulty sensors, such as the transmission range sensor or vehicle speed sensor, if necessary.
4. If the TCM is determined to be faulty, replace it with a new or remanufactured unit.
5. After repairs, clear the DTC using an OBD-II scanner and take the vehicle for a test drive to ensure the issue is resolved.

How to erase DTC P1739

To erase DTC P1739, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Access the scanner’s menu and select the option to clear or erase trouble codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and start the vehicle to check if the code reappears.

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