AutoCodes – GMC – U18D2 GMC

U18D2 GMC Code - Lost Communication With Transmission Range Selector Control Module On Powertrain Sensor CAN Bus

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Transmission Range Control Module, Transmission Range Control Module harness is open or shorted, Transmission Range Control Module circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U18D2 GMC indicates Lost Communication With Transmission Range Selector Control Module On Powertrain Sensor CAN Bus.
Common causes: Common causes include Faulty Transmission Range Control Module, Transmission Range Control Module harness is open or shorted, Transmission Range Control Module circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 909

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18D2 GMC Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U18D2 GMC - Lost Communication With Transmission Range Selector Control Module On Powertrain Sensor CAN Bus - AutoCodes.com — U18D2 GMC Code - Lost Communication With Transmission Range Selector Control Module On Powertrain Sensor CAN Bus

What does this mean?

What are the Possible Causes of the DTC U18D2 GMC?

Faulty Transmission Range Control Module
Transmission Range Control Module harness is open or shorted
Transmission Range Control Module circuit poor electrical connection

How to Fix the DTC U18D2 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U18D2 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U18D2 GMC Code

1. What are common symptoms of OBDII code U18D2 GMC?

- Common symptoms include transmission shifting issues, stalling, loss of power, and the transmission remaining in one gear.

2. What can cause the OBDII code U18D2 GMC to appear?

- The code can be triggered by a malfunction in the Transmission Range Selector Control Module or issues with the Powertrain Sensor CAN Bus communication.

3. How can I diagnose the cause of the U18D2 code in my GMC vehicle?

- Diagnosing the issue typically involves checking the connections to the Transmission Range Selector Control Module, inspecting the wiring harness for damage, and scanning for any other related trouble codes.

4. Can I drive my GMC with the U18D2 code present?

- It is not recommended to drive the vehicle with this code present, as it can lead to further transmission problems and potential safety hazards.

5. How can I repair the U18D2 code on my GMC?

- Repairing the code may involve repairing or replacing the Transmission Range Selector Control Module, fixing any damaged wiring, or addressing communication issues on the Powertrain Sensor CAN Bus.

6. Is it possible to reset the U18D2 code without fixing the underlying issue?

- While clearing the code may temporarily remove the warning light, it is important to address the root cause of the problem to prevent it from reoccurring.

7. Can a DIY enthusiast fix the U18D2 code issue?

- Depending on the level of expertise and access to tools, some DIY enthusiasts may be able to address the U18D2 code by checking connections, inspecting wiring, and potentially replacing components.

8. How much does it typically cost to repair the U18D2 code in a GMC vehicle?

- Repair costs can vary depending on the specific issue, but they may range from a few hundred to a few thousand dollars, including parts and labor.

9. Are there any preventive measures to avoid the U18D2 code in the future?

- Regular maintenance, such as checking and cleaning electrical connections, inspecting wiring harnesses, and addressing any transmission issues promptly, can help prevent the recurrence of the U18D2 code.

10. Can the U18D2 code be related to other transmission problems in a GMC vehicle?

- Yes, the U18D2 code can be related to other transmission issues due to its impact on communication between the Transmission Range Selector Control Module and the Powertrain Sensor CAN Bus.