AutoCodes – Cadillac – B3874 Cadillac

B3874 Cadillac Code - Wiper Low Speed Relay Circuit

Quick Answer

The Body Control Module (BCM) controls and monitors the state of the wiper control circuit. Common causes include Faulty Wiper Low Speed Relay, Wiper Low Speed Relay harness is open or shorted, Wiper Low Speed 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: B3874 Cadillac indicates Wiper Low Speed Relay Circuit.
Common causes: Common causes include Faulty Wiper Low Speed Relay, Wiper Low Speed Relay harness is open or shorted, Wiper Low Speed 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 402

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 B3874 Cadillac Description

The Body Control Module (BCM) controls and monitors the state of the wiper control circuit. When the windshield wiper switch is placed in to a low speed setting, a signal is applied to the BCM. The BCM then applies the battery positive voltage to the coil side of the relay through the relay control circuit. The Diagnostic Trouble Code (DTC) sets when the ignition is in the ON position or the ignition voltage is between 9-16 volts.

OBDII Code B3874 Cadillac - Wiper Low Speed Relay Circuit - AutoCodes.com — B3874 Cadillac Code - Wiper Low Speed Relay Circuit

What does this mean?

What are the Possible Causes of the DTC B3874 Cadillac?

Faulty Wiper Low Speed Relay
Wiper Low Speed Relay harness is open or shorted
Wiper Low Speed Relay circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3874 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 B3874 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.

Need more information about the B3874 Cadillac 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 B3874 Cadillac Code

1. What are the common symptoms of OBDII code B3874 (Cadillac) related to the Wiper Low Speed Relay Circuit?

- Common symptoms include wiper blades moving at an incorrect speed or not moving at all on the low setting.

2. What are the potential causes of OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- Possible causes include a faulty wiper relay, damaged wiring or connectors, or a malfunctioning wiper motor.

3. How can I diagnose OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- Diagnosis involves using a scan tool to retrieve the trouble code, inspecting the wiper relay and related components, and testing the circuit for continuity and proper voltage.

4. What repair tips can help fix OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- Repair tips include replacing the faulty wiper relay, repairing any damaged wiring or connectors, and ensuring proper grounding of the wiper system.

5. Is it safe to continue driving with OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- It is not recommended to drive with this issue as it can affect the proper functioning of your wipers, compromising visibility during inclement weather.

6. Can a DIY enthusiast fix OBDII code B3874 (Cadillac) related to the Wiper Low Speed Relay Circuit?

- Depending on their skill level, DIY enthusiasts can attempt to fix this issue by following repair guides and using the necessary tools and replacement parts.

7. How much does it typically cost to repair OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- The cost of repairs can vary based on the specific cause of the issue, but it may range from $50 to $200 for parts and labor.

8. Are there any preventive measures to avoid OBDII code B3874 (Cadillac) related to the Wiper Low Speed Relay Circuit?

- Regularly inspecting and maintaining the wiper system, including cleaning the blades and ensuring proper operation, can help prevent issues that trigger this trouble code.

9. Can extreme weather conditions contribute to triggering OBDII code B3874 (Cadillac) for the Wiper Low Speed Relay Circuit?

- Yes, extreme weather conditions such as heavy rain, snow, or ice can put additional strain on the wiper system, potentially leading to issues with the low-speed relay circuit.

10. How long does it typically take to repair OBDII code B3874 (Cadillac) related to the Wiper Low Speed Relay Circuit?

- The repair time can vary depending on the specific cause of the issue and the availability of parts, but it may take anywhere from 1 to 3 hours at a repair shop.