Encountering a check engine light in your 2015 Dodge Dart can be concerning, especially when it’s accompanied by an unfamiliar OBD2 code. One code that has been reported by Dodge Dart owners, particularly those who perform DIY modifications or disconnect their vehicle’s battery, is U1504. This code, while sometimes alarming, often has a straightforward explanation and resolution, especially in models from 2014 onwards. Let’s delve into what the U1504 code means for your 2015 Dodge Dart and how to address it.
Decoding OBD2 Code U1504: Lost Communication with Steering Angle Sensor
The OBD2 (On-Board Diagnostics II) system is your car’s built-in monitoring system. When something isn’t working correctly, it triggers a “check engine light” and stores a diagnostic trouble code (DTC) to help identify the problem area. Code U1504 is defined as “Lost Communication With Steering Angle Sensor Module” on the Controller Area Network (CAN) bus.
To break this down:
- OBD2 Code: A standardized code used across the automotive industry to identify vehicle issues.
- U1504: Specifically points to a communication problem. The “U” indicates it’s a network communication code.
- Lost Communication: Signifies that modules within your car’s network are unable to communicate properly.
- Steering Angle Sensor (SAS): This sensor is crucial for systems like electronic stability control (ESC) and power steering. It measures the steering wheel’s position and angle.
- Module: Refers to an electronic control unit (ECU) or computer within the car.
- CAN Bus (Controller Area Network): Think of this as the central nervous system of your car’s electronics. It’s a network that allows various modules (like the engine control unit, transmission control unit, ABS module, and in this case, the Steering Angle Sensor Module) to communicate with each other.
Alt text: Locating the OBD2 port in a vehicle for diagnostic scanning, essential for reading error codes like U1504 in a 2015 Dodge Dart.
Why Does U1504 Appear in 2015 Dodge Darts After Battery Disconnection?
The most common reason for the U1504 code to surface in 2015 and later Dodge Dart models is disconnecting and reconnecting the vehicle’s battery. This is particularly noted when performing electrical modifications, such as installing aftermarket lighting like HIDs or LEDs, or even routine maintenance that requires battery disconnection.
Here’s why this happens:
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Steering Angle Sensor Calibration: The Steering Angle Sensor often requires calibration or a relearning process after power is interrupted. When you disconnect the battery, you’re essentially cutting power to all modules, including the SAS module. Upon reconnection, the SAS module might temporarily lose its calibrated position or its ability to communicate seamlessly with other modules on the CAN bus.
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CAN Bus Communication Glitch: Disconnecting the battery can sometimes cause a temporary disruption in the CAN bus communication network. When power is restored, modules need to re-establish communication. During this brief period, the SAS module might not immediately communicate correctly, triggering the U1504 “Lost Communication” code.
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Software Differences in Later Models (2014+ vs. 2013): As highlighted in the original forum discussions, 2013 Dodge Darts and earlier models didn’t seem to exhibit this U1504 issue after battery disconnection as frequently as 2014 and newer models. This suggests potential changes in the vehicle’s software or electronic architecture from 2014 onwards that made them more sensitive to battery disconnection in relation to the Steering Angle Sensor communication.
Alt text: A dashboard view showing the check engine light illuminated in a Dodge Dart, indicating a potential issue like OBD2 code U1504.
Is OBD2 Code U1504 in a 2015 Dodge Dart Serious?
In most cases, when U1504 appears after a battery disconnect in a 2015 Dodge Dart, it is not indicative of a serious mechanical or electrical fault. It’s more of a temporary electronic hiccup. Many Dodge Dart owners have reported that this code is transient and often clears itself after a few engine start cycles or after driving a short distance.
Here’s why you likely don’t need to panic:
- Self-Clearing Nature: The code is designed to trigger when communication is lost, but if communication is quickly re-established, the system is often programmed to recognize this and clear the code automatically.
- No Immediate Performance Issues: Typically, a U1504 code caused by battery disconnection doesn’t result in noticeable drivability problems. The steering, braking, and stability control systems usually continue to function normally.
However, consider these points:
- Persistent Code: If the U1504 code does not clear after several driving cycles (e.g., 8-10 engine starts and stops with some driving in between), or if it reappears frequently without battery disconnection, then it might indicate a more persistent issue.
- Other Symptoms: If the check engine light is accompanied by other warning lights (like ABS or ESC lights) or if you notice issues with steering, stability control, or other vehicle systems, then further investigation is warranted.
Troubleshooting and Clearing U1504 Code in Your 2015 Dodge Dart
Here are steps you can take to address the U1504 code after battery disconnection:
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Wait and Drive: The simplest approach is often to wait. Drive your Dodge Dart normally for a few days, completing several engine start and stop cycles. In many instances, the U1504 code will clear itself as the system recalibrates and communication stabilizes.
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Use an OBD2 Scanner: If you want to clear the code immediately, you can use an OBD2 scanner. These scanners are readily available online or at auto parts stores.
- Read Codes: Plug the scanner into your Dodge Dart’s OBD2 port (usually located under the dashboard on the driver’s side). Turn the ignition to the “ON” position (engine off) and use the scanner to read the stored codes.
- Clear Codes: Select the option to clear codes. This will erase the U1504 code and turn off the check engine light.
Alt text: Using an OBD2 scanner to diagnose and clear error codes such as U1504 in a 2015 Dodge Dart, a common practice for DIY car maintenance.
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Professional Scan (If Necessary): If the code persists, or if you are experiencing other symptoms, it’s wise to have your Dodge Dart scanned by a professional mechanic or at a Dodge dealership. They have more advanced diagnostic tools and expertise to identify any underlying issues if the U1504 code is not just a transient glitch.
Preventative Measures (Limited):
Unfortunately, there’s no guaranteed way to prevent the U1504 code from appearing in 2014+ Dodge Darts after battery disconnection. It seems to be a characteristic of the vehicle’s electronic system. However, being aware that this code might appear can alleviate concern if it does.
Conclusion
The OBD2 code U1504 in a 2015 Dodge Dart, especially after battery disconnection, is often a benign and self-correcting issue related to Steering Angle Sensor communication. While it can be initially concerning to see a check engine light, understanding the cause and knowing that it typically resolves itself can provide peace of mind. If the code persists or is accompanied by other problems, don’t hesitate to seek professional diagnostic help to ensure your vehicle is functioning correctly.
