AutoCodes – GMC – P155A 2018 GMC Sierra

P155A 2018 GMC Sierra Code - Cruise Control Switch State Undetermined

Quick Answer

The Cruise Control Switch is an input to the Body Control Module (BCM). Common causes include Faulty Cruise Control Switch, Cruise Control Switch harness is open or shorted, Cruise Control 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: P155A 2018 GMC Sierra indicates Cruise Control Switch State Undetermined.
Common causes: Common causes include Faulty Cruise Control Switch, Cruise Control Switch harness is open or shorted, Cruise Control 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 254

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 Mar 25, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P155A 2018 GMC Sierra Description

The Cruise Control Switch is an input to the Body Control Module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate and cancel switches via the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied. The Engine Control Module (ECM) receives the requested cruise control switch function from the BCM via a serial data message. The Diagnostic Trouble Code (DTC) will be set when the ECM is unable to determine the state of the cruise control switch.

OBDII Code P155A 2018 GMC Sierra - Cruise Control Switch State Undetermined - AutoCodes.com — P155A 2018 GMC Sierra Code - Cruise Control Switch State Undetermined

What does this mean?

What are the Possible Causes of the DTC P155A 2018 GMC Sierra?

Faulty Cruise Control Switch
Cruise Control Switch harness is open or shorted
Cruise Control Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC P155A 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 P155A 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 P155A 2018 GMC Sierra code?

Need more information on how to fix the P155A 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the 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 P155A 2018 GMC Sierra Code

1. What does OBDII code P155A mean for a 2018 GMC Sierra?

The code P155A on a 2018 GMC Sierra indicates a Cruise Control Switch State Undetermined issue.

2. What are the common symptoms of OBDII code P155A in a 2018 GMC Sierra?

Common symptoms of code P155A in a 2018 GMC Sierra may include inoperative cruise control, illuminated warning lights on the dashboard, and potential issues with vehicle speed control.

3. What are the possible causes of OBDII code P155A in a 2018 GMC Sierra?

Possible causes of code P155A in a 2018 GMC Sierra include faulty cruise control switch, wiring issues, damaged cruise control system components, or a malfunctioning cruise control module.

4. How can I diagnose OBDII code P155A in my 2018 GMC Sierra?

Diagnosing code P155A in a 2018 GMC Sierra involves using an OBDII scanner to retrieve the fault code, inspecting the cruise control system components for any visible damage, and conducting a thorough electrical system check.

5. Is it safe to continue driving my 2018 GMC Sierra with OBDII code P155A?

It is generally not recommended to drive your 2018 GMC Sierra with an unresolved OBDII code P155A, as it can lead to potential safety issues related to cruise control functionality.

6. Can I repair OBDII code P155A in my 2018 GMC Sierra myself?

Depending on your level of automotive expertise, you may be able to repair code P155A in your 2018 GMC Sierra yourself by addressing the identified cause, such as replacing a faulty cruise control switch or repairing damaged wiring.

7. How much does it typically cost to repair OBDII code P155A in a 2018 GMC Sierra?

The cost of repairing OBDII code P155A in a 2018 GMC Sierra can vary depending on the specific cause of the issue, labor rates in your area, and whether you choose to address the problem yourself or take it to a professional mechanic.

8. Will resetting the OBDII code P155A in my 2018 GMC Sierra make it go away permanently?

Resetting the OBDII code P155A in a 2018 GMC Sierra may temporarily clear the fault code, but if the underlying issue is not addressed, the code is likely to reappear once the problem resurfaces.

9. Can a faulty cruise control system cause OBDII code P155A in a 2018 GMC Sierra?

Yes, a faulty cruise control system, including components like the cruise control switch or module, can trigger OBDII code P155A in a 2018 GMC Sierra due to issues with the switch state being undetermined.

10. How important is it to address OBDII code P155A in a timely manner for a 2018 GMC Sierra?

It is important to address OBDII code P155A promptly in a 2018 GMC Sierra to ensure the proper functioning of the cruise control system and maintain safe driving conditions.