AutoCodes – Hyundai – P1631 Hyundai

P1631 Hyundai Code - TCU Communication Line Malfunction

Quick Answer

The TCM can either receive data from the Engine Control Module or ABS control module, or it can send data to the ECM and ABSCM by using CAN communication. Common causes include Open or Short in CAN communication harness, Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted. 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: P1631 Hyundai indicates TCU Communication Line Malfunction.
Common causes: Common causes include Open or Short in CAN communication harness, Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted.
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 16,298

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 Aug 17, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1631 Hyundai Description

The TCM can either receive data from the Engine Control Module or ABS control module, or it can send data to the ECM and ABSCM by using CAN communication. CAN communication is one of the vehicle communications methods, which is now widely used to transfer vehicle data.

OBDII Code P1631 Hyundai - TCU Communication Line Malfunction - AutoCodes.com — P1631 Hyundai Code - TCU Communication Line Malfunction

What does this mean?

What are the Possible Causes of the DTC P1631 Hyundai?

Open or Short in CAN communication harness
Faulty Transmission Control Module (TCM)
Transmission Control Module harness is open or shorted
Transmission Control Module circuit poor electrical connection

How to Fix the DTC P1631 Hyundai?

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 P1631 Hyundai 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 P1631 Hyundai Code

1. What does the OBDII code P1631 Hyundai mean?

The P1631 code in Hyundai vehicles indicates a TCU Communication Line Malfunction, signaling a problem with the transmission control module's communication network.

2. What are common symptoms of a TCU Communication Line Malfunction?

Common symptoms include transmission shifting issues, decreased fuel efficiency, illuminated Check Engine Light, and potentially the vehicle going into limp mode.

3. What are possible causes of the TCU Communication Line Malfunction code?

Potential causes include damaged wiring or connectors in the communication line, a faulty transmission control module, software issues, or a problem with the CAN bus system.

4. How can I diagnose the TCU Communication Line Malfunction in my Hyundai?

Diagnosis typically involves using a diagnostic scanner to read the code, checking for related codes, inspecting the wiring and connectors, and performing tests on the transmission control module.

5. Can I still drive my Hyundai with the P1631 code present?

It is not recommended to drive the vehicle with the TCU Communication Line Malfunction code as it can lead to further damage and safety issues. It is best to address the problem promptly.

6. How can I repair a TCU Communication Line Malfunction in my Hyundai?

Repair options may include repairing or replacing damaged wiring or connectors, reprogramming the transmission control module, or replacing the TCU if it is found to be faulty.

7. Is it necessary to reset the code after repairing the TCU Communication Line issue?

Yes, it is important to clear the code after repairing the problem to reset the Check Engine Light and ensure the issue has been resolved successfully.

8. Can a DIY enthusiast fix the TCU Communication Line Malfunction code?

While some basic troubleshooting like checking connections can be done by DIYers, diagnosing and repairing complex issues related to the TCU communication line may require professional expertise.

9. How much does it cost to repair a TCU Communication Line Malfunction in a Hyundai?

The cost of repair can vary depending on the exact cause of the issue, parts needed, and labor rates. It is advisable to get a diagnostic done to determine the precise repair cost.

10. How can I prevent the TCU Communication Line Malfunction from occurring again?

Regular maintenance, timely inspections, and addressing any transmission-related issues promptly can help prevent the recurrence of the TCU Communication Line Malfunction in your Hyundai.