AutoCodes – Buick – P155A Buick

P155A Buick 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 Buick 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 1,215

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 Buick 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 Buick - Cruise Control Switch State Undetermined - AutoCodes.com — P155A Buick Code - Cruise Control Switch State Undetermined

What does this mean?

What are the Possible Causes of the DTC P155A Buick?

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 Buick?

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 Buick 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 P155A Buick Code

1. What does the OBDII code P155A mean on a Buick?

P155A indicates that the cruise control switch state is undetermined, meaning the engine control module (ECM) is unable to interpret the position or status of the cruise control switch.

2. What are the common symptoms of code P155A on a Buick?

Symptoms may include cruise control not working, an illuminated check engine light, or inconsistent cruise control behavior.

3. What causes the P155A code to appear on a Buick?

Possible causes include a faulty cruise control switch, wiring issues such as damaged or corroded connectors, or a malfunctioning ECM.

4. Can I still drive my Buick with the P155A code?

Yes, you can still drive your vehicle, but the cruise control function may not work, and ignoring the issue could lead to more significant problems over time.

5. How is the P155A code diagnosed on a Buick?

A technician will use a scan tool to confirm the code, inspect the cruise control switch and its wiring, and possibly perform voltage or continuity tests to determine the root cause.

6. How do I fix the P155A code on my Buick?

Repairs may involve replacing the cruise control switch, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming the ECM if necessary.

7. How much does it cost to fix the P155A code on a Buick?

The cost can vary but typically ranges from $100 to $300 depending on whether the issue is with the switch, wiring, or ECM.

8. Can a dead battery cause the P155A code on a Buick?

While unlikely, a dead or weak battery could cause electrical system malfunctions that might indirectly trigger the code.

9. Is it necessary to replace the cruise control switch for the P155A code?

Not always. Sometimes the issue can be resolved by repairing wiring or cleaning connectors, but if the switch is confirmed faulty, replacement is necessary.

10. Will clearing the code fix the P155A issue permanently?

Clearing the code may temporarily turn off the warning light, but the issue will likely return unless the underlying problem is resolved.