U0751 - Understanding DTC U0751: Common Issues in 2015-2018 Chevrolet Silverado and GMC Sierra

Quick Answer

U0751 means: U0751 indicates a communication failure between the transmission control module and engine control module.

Fix: Check and replace faulty components Cost: $300 - $800 Time: 90-180 minutes

Can I drive with U0751? Immediate attention is recommended to prevent further transmission damage.

Common Questions

What does U0751 mean and how does it affect my car?

DTC U0751 indicates a communication failure between your vehicle’s transmission control module and engine control module. This can lead to performance issues such as erratic shifting, decreased fuel efficiency, and even a no-start condition. Addressing this code quickly is crucial to maintain optimal vehicle performance and prevent further damage.

What are the most common causes of U0751 and how much does it cost to fix?

Common causes include a faulty transmission control module, wiring issues, or software glitches. Repair costs can vary significantly, ranging from $100 for wiring repairs to $800 for TCM replacement. It's best to have a diagnostic performed to pinpoint the exact issue.

Can I drive my car with U0751 or should I stop immediately?

Driving with U0751 is not advisable as it may lead to further damage and safety concerns. If the vehicle enters limp mode, it will limit your driving capabilities, so it's best to address this issue as soon as possible.

How can I diagnose U0751 myself using GeekOBD APP?

Using the GeekOBD APP, you can scan for DTCs and view freeze-frame data to understand the context of the fault. Check for any additional codes that may provide insight into related issues, and follow up with visual inspections of wiring and connections.

What vehicles are most commonly affected by U0751?

DTC U0751 is frequently seen in 2015-2018 Chevrolet Silverado and GMC Sierra models. Other vehicles may also be affected, so it's important to check specific manufacturer bulletins for more details.

How can I prevent U0751 from happening again?

Regular maintenance is key. Ensure timely transmission fluid changes, inspect wiring and connections frequently, and keep software updated to prevent potential issues from arising.

What is U0751?

The diagnostic trouble code (DTC) U0751 indicates a communication issue between the transmission control module (TCM) and the engine control module (ECM). This code often points to a problem in the CAN (Controller Area Network) communication bus, which is critical for proper vehicle operation. When the TCM fails to receive or send data to the ECM, it can lead to various operational issues such as erratic shifting, reduced engine performance, or even a no-start condition. In real-world situations, this can manifest as the check engine light illuminating, and may also cause your vehicle to enter a 'limp mode,' where it restricts functionality to prevent further damage. It’s important to address this code promptly, as ignoring it can lead to more severe transmission problems or engine performance issues over time. This code is particularly common in certain models like the 2015-2018 Chevrolet Silverado and GMC Sierra but can affect other vehicles as well. If you see this code, a thorough diagnostic process is essential to identify the root cause and prevent further complications.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0751 is present:

The check engine light stays on constantly, indicating a fault in the vehicle's electronic systems.
Drivers may experience engine hesitation during acceleration, making it difficult to maintain speed.
Fuel economy may decrease by 10-15%, as the engine and transmission are not communicating efficiently.
Shifting issues can occur, such as hard shifts or slipping of the transmission.
In severe cases, the vehicle may enter limp mode, restricting your ability to drive normally.

Possible Causes

Most common causes of U0751 (ordered by frequency):

{'cause': 'Faulty Transmission Control Module (TCM)', 'likelihood': '50%', 'details': 'A malfunctioning TCM can disrupt the communication between the ECM and TCM, leading to U0751.'}
{'cause': 'Wiring Issues or Poor Connections', 'details': 'Corroded or damaged wiring in the CAN bus can prevent proper communication. Regular inspections can help prevent this.'}
{'cause': 'Software Glitches', 'details': "Outdated or faulty software in the ECM or TCM can cause communication errors. Keeping your vehicle's software updated is crucial."}
{'cause': 'Transmission Fluid Issues', 'details': 'Low or contaminated transmission fluid can lead to shifting problems and may indirectly cause U0751. Regular fluid checks are recommended.'}
{'cause': 'Defective Engine Control Module (ECM)', 'details': 'Though less common, a faulty ECM can also result in code U0751 due to improper signal processing.'}

U0751 Repair Costs

Cost Breakdown by Repair Type

Replace Transmission Control Module

Replacing the TCM is often necessary if it is found to be defective.

Total: $300 - $800
Success rate: 85%

Repair Wiring and Connectors

Repairing or replacing damaged wiring and connectors in the CAN bus.

Total: $100 - $300
Success rate: 70%

Software Update

Updating the TCM and ECM software to the latest version.

Total: $50 - $150
Success rate: 60%

Money-Saving Tips for U0751

Start with the most common and least expensive repairs first
Use GeekOBD APP to confirm diagnosis before replacing expensive parts
Consider preventive maintenance to avoid future occurrences
Compare prices for OEM vs aftermarket parts based on your needs
Address the issue promptly to prevent more expensive secondary damage

Diagnostic Steps

Professional U0751 Diagnosis Process

Follow these systematic steps to accurately diagnose U0751. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Check for obvious signs of damage, such as frayed wiring, loose connections, or corrosion around both the TCM and ECM (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs of damage, such as frayed wiring, loose connections, or corrosion around both the TCM and ECM (5-10 minutes).