AutoCodes – Cadillac – B3881 Cadillac

B3881 Cadillac Code - Left Tail Lamp Circuit Short to Ground

Quick Answer

The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. Common causes include Faulty Left Tail Lamp, Left Tail Lamp harness is open or shorted, Left Tail Lamp 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: B3881 Cadillac indicates Left Tail Lamp Circuit Short to Ground.
Common causes: Common causes include Faulty Left Tail Lamp, Left Tail Lamp harness is open or shorted, Left Tail Lamp 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 513

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 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3881 Cadillac Description

The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The Body Control Module (BCM) provides a low reference signal and a 5 V reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM will apply battery voltage to the left and right stop lamp control circuits as well as the center high mounted stop lamp relay control circuit illuminating the left and right stop lamps and the center high mounted stop lamp. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground in the left stop lamp control circuit.

OBDII Code B3881 Cadillac - Left Tail Lamp Circuit Short to Ground - AutoCodes.com — B3881 Cadillac Code - Left Tail Lamp Circuit Short to Ground

What does this mean?

What are the Possible Causes of the DTC B3881 Cadillac?

Faulty Left Tail Lamp
Left Tail Lamp harness is open or shorted
Left Tail Lamp circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3881 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 B3881 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 B3881 Cadillac Code

1. What does the OBDII code B3881 mean on a Cadillac?

The B3881 code indicates a "Left Tail Lamp Circuit Short to Ground," meaning there's an issue in the wiring or connection for the left tail lamp causing a short.

2. What are the common symptoms of code B3881 on a Cadillac?

Common symptoms include the left tail lamp not working, flickering, or staying off entirely, and possibly a warning on the dashboard.

3. What causes the B3881 code to appear on a Cadillac?

The code is typically caused by damaged wiring, a faulty bulb, a corroded connector, or a short circuit in the left tail lamp circuit.

4. Can I drive my Cadillac with the B3881 code active?

Yes, but itâ€™s not recommended as a non-functioning tail lamp reduces visibility at night and could lead to safety issues or legal violations.

5. How do I troubleshoot the B3881 code on my Cadillac?

Start by inspecting the left tail lamp bulb, wiring, and connectors for damage or corrosion. Use a multimeter to check for continuity and shorts in the circuit.

6. Does the B3881 code mean the left tail lamp bulb is bad?

Not necessarily. While a faulty bulb is a common cause, the issue could also lie in the wiring, connectors, or control module.

7. How do I fix the B3881 code on a Cadillac?

Repairs may involve replacing a damaged bulb, repairing or replacing faulty wires, cleaning corroded connectors, or addressing a fault in the control module.

8. Will clearing the B3881 code fix the problem?

Clearing the code will reset the warning temporarily, but the underlying issue must be resolved to prevent the code from returning.

9. How much does it cost to repair the B3881 code on a Cadillac?

Costs vary depending on the problem but can range from $10 for a new bulb to $100+ if professional wiring repairs are needed.

10. Can a faulty fuse cause the B3881 code?

A blown or faulty fuse could indirectly cause the issue by interrupting the circuit, but the B3881 code specifically points to a short to ground in the tail lamp wiring.