Ford U1900: CAN Communication Bus Fault (Receive Error)

Is your scanner showing Ford U1900?
No worries. We'll show you what it means and how to deal with it.

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Ford U1900: CAN Communication Bus Fault (Receive Error)

OVERVIEW

Severity

Medium

DIY Difficulty Level

Intermediate

Repair Cost

$0-$300

Can I Still Drive?

Yes (Short-term only)

What Does The Ford U1900 Code Mean?

U1900 on Ford is a Diagnostic Trouble Code (DTC) specific to Ford vehicles, indicating a communication problem within the Controller Area Network (CAN) bus system. The CAN bus is responsible for facilitating communication between various electronic modules in the vehicle, including the ABS control module, instrument cluster, trailer brake controller, etc. When the U1900 code appears, it typically suggests a fault in the network, causing a loss of communication between one or more modules and the PCM.

Warning lights come on on the dashboard when getting the U1900 trouble code. (Credit: https://www.taurusclub.com/)

What Are The Symptoms Of The Ford U1900 Code?

The U1900 code and the associated communication problem between modules can lead to various symptoms in a Ford vehicle. These symptoms can vary depending on the specific module(s) affected and the severity of the communication issue. Some common symptoms include:

Check Engine Light illuminated
Erratic or non-functional instrument cluster
ABS Light ON

What Are The Potential Causes Of The Ford U1900 Code?

The lack of communication can result from:

Wiring issues
Faulty connections
Defective instrument cluster
Faulty trailer brake controller
Bad ABS Module

How Serious Is This Ford U1900 Code?

The U1900 code in Ford vehicles is of high severity due to its potential to impact critical vehicle systems, leading to drivability problems. It indicates a communication issue within the CAN bus system, which can affect engine performance, transmission shifting, and safety systems like ABS and airbags.

So, can you still drive with this code? The answer is NO. Driving with the U1900 code is not recommended. The U1900 code specifically indicates a communication problem between modules, which can affect various vehicle functions, including safety systems and drivability. It’s essential to address this issue immediately and avoid driving the vehicle until it is properly diagnosed and repaired.

How Can You Fix The Ford U1900 Code?

Fixing the U1900 DTC requires a systematic approach to identify and resolve the communication problem within the CAN bus system in Ford vehicles.

Tools & Parts Required:

OBDII Scanner
Multimeter
Wiring diagram
Repair Manual
Wiring Harness
Connectors Terminals
Fuses and Relays
Modules

Here’s a step-by-step guide on how to fix this code:

Step 1: Perform a Diagnosis

Use a suitable diagnostic scan tool to retrieve the specific trouble code(s) and access the vehicle’s onboard computer systems. This will help pinpoint the module(s) involved in the communication issue.

Step 2: Inspect Wiring and Connections

inspect the wiring harness and connectors related to the affected module(s). Thoroughly examine them for any indications of damage, loose connections, or corrosion. Repair or replace any faulty components as needed.

Step 3: Check Fuse and Relay

Verify the status of relevant fuses and relays that may affect the CAN bus system. A blown fuse or malfunctioning relay could lead to communication problems.

Step 4: Test Modules

Perform individual tests on the modules involved in the communication issue. Test for power supply, ground, and communication signals to ensure proper functioning.

Step 5: Update Software and Calibration

Check for available software updates or calibrations for the affected modules. Manufacturers often release updates to address known issues and improve system performance.

Step 6: Clear Trouble Codes

After repairs are completed, use the diagnostic scan tool to clear the trouble codes from the vehicle’s memory.

Step 7: Test Drive

Take the vehicle for a test drive to ensure that the communication problem is resolved and that all systems are functioning correctly.

Step 8: Re-Scan for Codes

After the test drive, re-scan the vehicle to confirm that the U1900 code does not reappear. If the issue persists, additional diagnostics may be required.

It’s important to note that fixing the U1900 code can vary in complexity, depending on the specific cause and the modules involved. In many cases, diagnosing and resolving communication problems may require advanced diagnostic equipment and expertise. If you are not familiar with automotive diagnostics, it’s best to seek assistance from a qualified mechanic or a Ford dealership’s service center to ensure a proper and accurate repair.

If you found this article helpful and informative, please consider sharing it with others who might benefit from understanding the U1900 DTC and how to address communication issues within the CAN bus system in Ford vehicles. Don’t hesitate to leave a comment below if you have any related questions.