AutoCodes – GMC – P135D 2018 GMC Sierra

P135D 2018 GMC Sierra Code - Cooling Fan 2 Status Signals Message Counter Incorrect

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty Cooling Fan 2, Cooling Fan 2 harness is open or shorted, Cooling Fan 2 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: P135D 2018 GMC Sierra indicates Cooling Fan 2 Status Signals Message Counter Incorrect.
Common causes: Common causes include Faulty Cooling Fan 2, Cooling Fan 2 harness is open or shorted, Cooling Fan 2 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 145

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 Sep 27, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P135D 2018 GMC Sierra Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the Cooling Fan 2 Status Signals Message Counter is Incorrect.

OBDII Code P135D 2018 GMC Sierra - Cooling Fan 2 Status Signals Message Counter Incorrect - AutoCodes.com — P135D 2018 GMC Sierra Code - Cooling Fan 2 Status Signals Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P135D 2018 GMC Sierra?

Faulty Cooling Fan 2
Cooling Fan 2 harness is open or shorted
Cooling Fan 2 circuit poor electrical connection

How to Fix the DTC P135D 2018 GMC Sierra?

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 P135D 2018 GMC Sierra 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 P135D 2018 GMC Sierra code?

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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 P135D 2018 GMC Sierra Code

1. What does the OBDII code P135D mean on a 2018 GMC Sierra?

This code indicates an issue with the Cooling Fan 2 status signals, specifically that the message counter is incorrect or not updating as expected.

2. What are the symptoms of code P135D on a 2018 GMC Sierra?

Common symptoms include the check engine light turning on, irregular cooling fan operation, potential overheating, or reduced cooling efficiency.

3. What causes the P135D code to appear on a GMC Sierra?

The most common causes are faulty cooling fan modules, wiring or connector issues, or a malfunction in the Engine Control Module (ECM) communication with the cooling fan system.

4. Is it safe to drive with the P135D code on a 2018 GMC Sierra?

Driving with this code may be unsafe if the cooling fan is not functioning properly, as it could lead to engine overheating. It's best to address the issue promptly.

5. How can I diagnose the P135D code on my GMC Sierra?

Start by inspecting the cooling fan wiring and connectors for damage or corrosion. Use a diagnostic scan tool to verify the fan module communication and check for updates to the ECM software.

6. Can a faulty cooling fan module cause the P135D code?

Yes, a faulty cooling fan module is one of the primary causes of this code, as it may fail to send or receive proper status signals.

7. How do I fix the P135D code on a 2018 GMC Sierra?

Repairs may include replacing the cooling fan module, repairing damaged wiring or connectors, or reprogramming the ECM if necessary.

8. Will clearing the P135D code fix the problem permanently?

No, clearing the code will only remove it temporarily. The underlying issue must be repaired to prevent the code from returning.

9. Can a software update resolve the P135D code on my GMC Sierra?

In some cases, an ECM software update from the dealership may resolve communication issues that trigger the P135D code.

10. How much does it cost to repair the P135D code on a 2018 GMC Sierra?

Repair costs vary depending on the issue. Replacing a cooling fan module can cost between $300 and $600, while wiring repairs or ECM reprogramming may cost less.