U0104 - DTC U0104 - Lost Communication with the Engine Control Module (ECM) for Common Vehicles like 2014-2018 Ford F-150 and 2015-2019 Chevrolet Silverado

Quick Answer

U0104 means: U0104 indicates a communication loss between the ECM and TCM, potentially leading to performance issues.

Fix: Check and replace faulty components Cost: $150 - $400 Time: 90-180 minutes

Can I drive with U0104? It's advisable to investigate this issue immediately to avoid further damage.

Common Questions

What does U0104 mean and how does it affect my car?

The U0104 code signifies that your vehicle's Engine Control Module (ECM) is unable to communicate with the Transmission Control Module (TCM). This disruption can lead to various performance issues, including erratic shifts, loss of power, and even stalling. If you notice these symptoms, it's crucial to address the problem quickly to prevent further damage.

What are the most common causes of U0104 and how much does it cost to fix?

Common causes of U0104 include faulty wiring (60% likelihood) and malfunctioning ECM or TCM (25% likelihood). Repair costs can range from $150 for wiring repairs to over $1,200 for ECM replacement, depending on the severity of the issue and the parts required.

Can I drive my car with U0104 or should I stop immediately?

Driving with a U0104 code is not advisable as it can lead to significant performance issues and safety risks. If you experience any symptoms like stalling or erratic shifting, it's best to stop driving and have the vehicle diagnosed as soon as possible.

How can I diagnose U0104 myself using GeekOBD APP?

To diagnose U0104 with the GeekOBD APP, connect the scanner to your vehicle's OBD-II port, navigate to the DTC section, and retrieve all trouble codes. Pay close attention to any freeze frame data, which provides context about when the code was triggered, allowing for more accurate diagnostics.

What vehicles are most commonly affected by U0104?

Vehicles like the 2014-2018 Ford F-150 and 2015-2019 Chevrolet Silverado frequently experience U0104 due to their electronic systems. It's worth checking for any recalls or technical service bulletins (TSBs) related to this code for your specific vehicle.

How can I prevent U0104 from happening again?

Regular maintenance plays a vital role in preventing U0104. Ensure proper inspection of wiring harnesses, keep connectors clean, and regularly update your vehicle's software as recommended by the manufacturer.

What is U0104?

The diagnostic trouble code (DTC) U0104 indicates a communication failure between the Engine Control Module (ECM) and the Transmission Control Module (TCM). This code is particularly relevant for owners of vehicles such as the 2014-2018 Ford F-150 and the 2015-2019 Chevrolet Silverado. In essence, when the ECM cannot receive or send necessary data to the TCM, it can lead to a range of performance issues. Drivers may notice symptoms like erratic shifting, reduced engine power, or even stalling. The root cause could be anything from a faulty wiring harness to a malfunctioning module. If left unaddressed, this issue can significantly impact vehicle performance and safety, leading to costly repairs down the line. Therefore, understanding and addressing a U0104 code promptly is crucial for maintaining vehicle reliability.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0104 is present:

Check engine light illuminates continuously, indicating a persistent issue with the vehicle's system.
Transmission experiences harsh or erratic shifting, making the driving experience uncomfortable and potentially unsafe.
Engine power may feel diminished, especially under acceleration, which can lead to frustrating driving conditions.
Fuel economy drops noticeably, often by 10-20%, due to inefficient engine performance.
Vehicle may stall unexpectedly, posing a serious safety risk, especially in traffic.

Possible Causes

Most common causes of U0104 (ordered by frequency):

Faulty wiring harness (60% likelihood) - Damaged, corroded, or loose connections can disrupt communication between the ECM and TCM.
Malfunctioning ECM or TCM (25% likelihood) - An internal failure in either module can cause communication errors.
Software issues (10% likelihood) - Outdated or corrupted software might lead to improper functioning of the modules.
Poor ground connections (4% likelihood) - Insufficient grounding can result in intermittent communication failures.
Electrical interference (1% likelihood) - External electronic devices or faults can cause communication disruptions.

U0104 Repair Costs

Cost Breakdown by Repair Type

Wiring Harness Repair

Repair or replacement of damaged wiring connections.

Total: $150 - $400
Success rate: 80%

ECM Replacement

Replace faulty Engine Control Module with a new or refurbished unit.

Total: $600 - $1,200
Success rate: 90%

Software Update

Reprogramming or updating the ECM/TCM software.

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

Money-Saving Tips for U0104

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 U0104 Diagnosis Process

Follow these systematic steps to accurately diagnose U0104. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Check for damaged wiring, loose connections, or corrosion around the ECM and TCM (5-10 minutes)

Step 1: Initial visual inspection - Check for damaged wiring, loose connections, or corrosion around the ECM and TCM (5-10 minutes).