U1142 – OBD-II DTC

OBD-II DTC U1142 – SCP (J1850) Invalid or Missing Data for Primary Id

DTC U1142 meaning

DTC U1142 refers to a diagnostic trouble code that indicates an issue with the communication between modules in a vehicle’s network. Specifically, it signifies that there is invalid or missing data for the primary identifier in the SCP (Serial Communication Protocol) using the J1850 communication standard. This can occur when a module fails to send or receive the necessary data, leading to communication breakdowns within the vehicle’s systems.

DTC U1142 symptoms

Common symptoms associated with DTC U1142 may include:

• Warning lights illuminated on the dashboard, such as the check engine light.
• Malfunctioning vehicle features that rely on inter-module communication.
• Erratic behavior of electronic components, such as power windows or locks.
• Difficulty in starting the vehicle or intermittent stalling.

DTC U1142 causes

Several factors can lead to the occurrence of DTC U1142, including:

• Faulty or damaged wiring and connectors in the communication network.
• Defective control modules that are unable to communicate properly.
• Corrosion or poor connections at the module terminals.
• Software issues or bugs within the vehicle’s control modules.
• Interference from aftermarket devices or modifications.

DTC U1142 seriousness

The seriousness of DTC U1142 can vary depending on the specific symptoms and the vehicle’s reliance on the affected systems. While it may not pose an immediate safety risk, it can lead to further complications if left unaddressed. Continuous communication failures can result in more significant issues, affecting vehicle performance and reliability.

How to diagnose DTC U1142

To diagnose DTC U1142, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC and check for any related codes.
2. Inspect the vehicle’s wiring and connectors for any visible damage or corrosion.
3. Test the affected control modules for proper operation and communication.
4. Check for software updates or reprogramming needs for the control modules.
5. Perform a network test to ensure all modules are communicating correctly.

How to fix DTC U1142 step-by-step instructions

To fix DTC U1142, follow these steps:

1. Repair or replace any damaged wiring or connectors found during the inspection.
2. Replace any faulty control modules that are not communicating properly.
3. Clean any corroded connections to ensure good electrical contact.
4. Update or reprogram the control modules if necessary.
5. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC U1142

To erase DTC U1142, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s ignition without starting the engine.
3. Navigate to the DTC menu on the scanner and select the option to clear or erase codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

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.