AutoCodes – Generic – U1555

U1555 Code - Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus

Quick Answer

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. Common causes include Faulty Left Rear Seat Heating/Venting/Cooling Switch, Left Rear Seat Heating/Venting/Cooling Switch harness is open or shorted, Left Rear Seat Heating/Venting/Cooling Switch circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U1555 indicates Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus.
Common causes: Common causes include Faulty Left Rear Seat Heating/Venting/Cooling Switch, Left Rear Seat Heating/Venting/Cooling Switch harness is open or shorted, Left Rear Seat Heating/Venting/Cooling Switch circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,155

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1555 Description

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. The serial data is transmitted over a LIN circuit between a master control module and other LIN devices within a particular subsystem. If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) will set when a supervised periodic message to the Body Control Module (BCM) from the Left Rear Seat Heating/Venting/Cooling Switch has not been received.

OBDII Code U1555 - Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus - AutoCodes.com — U1555 Code - Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus

What does this mean?

What are the Possible Causes of the DTC U1555?

Faulty Left Rear Seat Heating/Venting/Cooling Switch
Left Rear Seat Heating/Venting/Cooling Switch harness is open or shorted
Left Rear Seat Heating/Venting/Cooling Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC U1555?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1555 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U1555 code?

Need more information on how to fix the U1555 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1555 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1555 Buick — Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus
U1555 Cadillac — Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus
U1555 Chevrolet — Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus
U1555 GMC — Body Control Module Lost Communication With Left Rear Seat Heating/Venting/Cooling Switch On LIN Bus

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U1555 Code

1. What are the common symptoms of OBDII code U1555 related to the Body Control Module losing communication with the left rear seat heating/cooling switch?

- Common symptoms include inoperative left rear seat heating/cooling functionality, malfunctioning seat vents, or issues with seat cooling features.

2. What are the possible causes of OBDII code U1555 indicating communication loss with the left rear seat heating/cooling switch?

- Potential causes include a faulty left rear seat heating/cooling switch, damaged wiring or connectors in the LIN bus network, or a malfunctioning Body Control Module.

3. How can I diagnose the issue causing OBDII code U1555 to determine if it's related to the left rear seat heating/cooling switch communication loss?

- Use a diagnostic scan tool to check for specific trouble codes, inspect the wiring and connectors associated with the left rear seat switch, and perform a LIN bus communication test.

4. Is it safe to continue driving with OBDII code U1555 triggered by the Body Control Module losing communication with the left rear seat heating/cooling switch?

- It is generally safe to drive, but it's recommended to address the issue promptly to ensure the proper functioning of the left rear seat heating/cooling system.

5. Are there any DIY repair tips for resolving OBDII code U1555 related to the communication loss with the left rear seat heating/cooling switch?

- DIY repair tips may include checking and repairing any damaged wiring, ensuring connectors are securely attached, and resetting the Body Control Module to see if communication is restored.

6. Can a professional mechanic help with diagnosing and repairing OBDII code U1555 associated with the left rear seat heating/cooling switch communication issue?

- Yes, a professional mechanic with experience in automotive diagnostics can accurately diagnose the problem, perform necessary repairs, and reset the system to clear the code.

7. How much does it typically cost to repair OBDII code U1555 related to the Body Control Module losing communication with the left rear seat heating/cooling switch?

- Repair costs can vary depending on the exact cause of the issue, but it may involve replacing the left rear seat switch, repairing wiring, or reprogramming the Body Control Module.

8. Will resetting the OBDII code U1555 resolve the communication problem with the left rear seat heating/cooling switch?

- Resetting the code may temporarily clear the fault, but it's crucial to address the underlying issue causing the communication loss to prevent the code from reoccurring.

9. Are there any recalls or technical service bulletins related to OBDII code U1555 and the Body Control Module's communication with the left rear seat heating/cooling switch?

- Check with the vehicle manufacturer or authorized dealerships to inquire about any recalls or technical service bulletins addressing this specific issue for your vehicle model.

10. How can I prevent OBDII code U1555 from occurring again after repairing the communication problem with the left rear seat heating/cooling switch?

- Regularly inspect and maintain the wiring and connectors associated with the left rear seat switch, follow recommended maintenance schedules, and address any related issues promptly to prevent code recurrence.