AutoCodes – Cadillac – U135B Cadillac

U135B Cadillac Code - Lost Communication With Sunload Sensor

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 Control Module Setting the Diagnostic Trouble Code (DTC), Control Module harness is open or shorted, Control Module 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: U135B Cadillac indicates Lost Communication With Sunload Sensor.
Common causes: Common causes include Faulty Control Module Setting the Diagnostic Trouble Code (DTC), Control Module harness is open or shorted, Control Module 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 404

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 May 16, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U135B Cadillac 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) sets when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U135B Cadillac - Lost Communication With Sunload Sensor - AutoCodes.com — U135B Cadillac Code - Lost Communication With Sunload Sensor

What does this mean?

What are the Possible Causes of the DTC U135B Cadillac?

Faulty Control Module Setting the Diagnostic Trouble Code (DTC)
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U135B Cadillac?

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 U135B Cadillac 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.

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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 U135B Cadillac Code

What does the OBDII code U135B mean for a Cadillac?

U135B indicates a lost communication with the sunload sensor, which measures the intensity of sunlight to help control climate settings.

What symptoms might indicate a U135B code?

Common symptoms include erratic climate control behavior, inconsistent temperature settings, and potential issues with the vehicleâ€™s HVAC system.

What could cause the U135B code to trigger?

Possible causes include a faulty sunload sensor, damaged wiring or connectors, or issues with the vehicleâ€™s electronic control unit (ECU).

How can I diagnose the U135B code?

Start by checking the sunload sensorâ€™s wiring and connectors for damage. Then, use an OBDII scanner to confirm the code and check for any other related codes.

What are some repair tips for the U135B code?

Inspect and repair any damaged wiring or connectors first. If the wiring is intact, consider replacing the sunload sensor. After repairs, clear the code and test drive the vehicle.

Will the U135B code affect vehicle performance?

While it may not directly affect engine performance, it can lead to uncomfortable cabin temperatures and reduced HVAC efficiency.

Can I drive my Cadillac with the U135B code?

Yes, you can drive the vehicle, but you may experience issues with climate control until the problem is resolved.

How much does it typically cost to repair the U135B code?

Repair costs can vary widely depending on the underlying issue, but replacing a sunload sensor typically ranges from $100 to $300, including parts and labor.

Is it necessary to reset the ECU after fixing the U135B code?

Yes, it is advisable to reset the ECU after repairs to clear the code and ensure that the system recalibrates properly.

Can the U135B code cause other problems in the vehicle?

While it primarily affects HVAC functionality, unresolved communication issues can potentially lead to other electrical system malfunctions if not addressed.