AutoCodes – Buick – B305E Buick

B305E Buick Code - Interruptible RAP Relay Circuit

Quick Answer

The Keyless Entry Control Module controls the retained accessory power relays through the control circuit by applying voltage to the interruptible retained accessory power relay coil control circuit. Common causes include Faulty Retained Accessory Power Relay, Retained Accessory Power Relay harness is open or shorted, Retained Accessory Power Relay 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: B305E Buick indicates Interruptible RAP Relay Circuit.
Common causes: Common causes include Faulty Retained Accessory Power Relay, Retained Accessory Power Relay harness is open or shorted, Retained Accessory Power Relay 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 736

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 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B305E Buick Description

The Keyless Entry Control Module controls the retained accessory power relays through the control circuit by applying voltage to the interruptible retained accessory power relay coil control circuit. The Retained Accessory Power Relays are energized when the ignition is in the ACCESSORY or the ON position. The relays are also energized for approximately 10 min after shutting the ignition OFF, providing no door is opened.

OBDII Code B305E Buick - Interruptible RAP Relay Circuit - AutoCodes.com — B305E Buick Code - Interruptible RAP Relay Circuit

What does this mean?

What are the Possible Causes of the DTC B305E Buick?

Faulty Retained Accessory Power Relay
Retained Accessory Power Relay harness is open or shorted
Retained Accessory Power Relay circuit poor electrical connection
Faulty Keyless Entry Control Module

How to Fix the DTC B305E 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 B305E 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 B305E Buick Code

1. What does the OBDII code B305E mean on a Buick?

The B305E code indicates an issue with the Interruptible Retained Accessory Power (RAP) Relay Circuit, which controls power to certain accessories after the ignition is turned off.

2. What are the common symptoms of the B305E code in a Buick?

Common symptoms include electrical accessories like the radio or power windows not functioning after the ignition is switched off, or they may fail to turn off as expected.

3. What causes the B305E code in a Buick?

The code can be triggered by a faulty RAP relay, damaged wiring or connectors in the RAP circuit, or a malfunctioning body control module (BCM).

4. Can a weak battery cause the B305E code in a Buick?

Yes, a weak or failing battery can cause voltage fluctuations that impact the RAP relay circuit, potentially triggering the B305E code.

5. How do you diagnose the B305E code in a Buick?

Diagnosis involves checking the RAP relay for proper operation, inspecting the wiring and connectors for damage or corrosion, and testing the BCM for faults.

6. Can the B305E code trigger other issues in a Buick?

Yes, if unresolved, it can lead to battery drain because accessories might stay powered on longer than intended.

7. How do you fix the B305E code in a Buick?

Repairs may include replacing the RAP relay, repairing damaged wiring, cleaning corroded connectors, or reprogramming or replacing the BCM if necessary.

8. Is the B305E code in a Buick urgent to fix?

While it may not impact drivability, it should be addressed promptly to prevent battery drain and ensure proper operation of electrical accessories.

9. How much does it cost to fix the B305E code in a Buick?

Repair costs vary but could range from $50 to $300 depending on whether the RAP relay, wiring, or BCM needs repair or replacement.

10. Can I clear the B305E code without fixing the issue?

Clearing the code without addressing the root cause may only provide a temporary fix, as the code will likely return if the underlying problem persists.