U1246 – OBD-II DTC

OBD-II DTC U1246 – SCP (J1850) Invalid or Missing Data for Primary Id

DTC U1246 meaning

DTC U1246 refers to a diagnostic trouble code indicating an issue with the Serial Communication Protocol (SCP) in vehicles using the J1850 communication standard. Specifically, it signifies that the primary identifier data is either invalid or missing. This can affect communication between various modules in the vehicle, leading to potential malfunctions in systems that rely on this data.

DTC U1246 symptoms

Common symptoms associated with DTC U1246 may include:

• Warning lights illuminated on the dashboard
• Loss of communication with certain vehicle modules
• Erratic behavior of electronic systems
• Inconsistent readings from sensors
• Difficulty in starting the vehicle

DTC U1246 causes

Several factors can lead to the occurrence of DTC U1246, including:

• Faulty wiring or connectors in the SCP network
• Defective vehicle control modules
• Corrosion or damage to the communication lines
• Software issues within the modules
• Interference from aftermarket devices

DTC U1246 seriousness

The seriousness of DTC U1246 can vary based on the symptoms and the systems affected. While it may not always indicate an immediate threat to vehicle safety, it can lead to:

• Inability to access certain vehicle functions
• Potential for further electrical issues
• Increased difficulty in diagnosing other related trouble codes

It is advisable to address this code promptly to prevent further complications.

How to diagnose DTC U1246

To diagnose DTC U1246, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC U1246.
2. Check for any additional trouble codes that may provide more context.
3. Inspect the wiring and connectors related to the SCP network for damage or corrosion.
4. Test the vehicle control modules for proper operation.
5. Verify the integrity of the communication lines using a multimeter.
6. Check for software updates or reprogramming needs for the modules.

How to fix DTC U1246 step-by-step instructions

To fix DTC U1246, follow these steps:

1. Repair or replace any damaged wiring or connectors found during diagnosis.
2. Replace any faulty vehicle control modules as necessary.
3. Clean any corrosion from connectors and ensure a secure fit.
4. Update or reprogram the software in the affected modules if required.
5. Clear the DTC using an OBD-II scanner and test drive the vehicle.
6. Monitor for the reoccurrence of the code or any related symptoms.

How to erase DTC U1246

To erase DTC U1246, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “On” position without starting the engine.
3. Access the trouble codes menu on the scanner.
4. Select the option to clear or erase trouble codes.
5. Confirm the action and wait for the scanner to complete the process.
6. Disconnect the scanner and start the vehicle to ensure the code does not return.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.