AutoCodes – Generic – B1C77

B1C77 Code - Rear Wiper Relay Circuit

Quick Answer

The Body Control Module (BCM) monitors the Rear Wiper Relay. Common causes include Faulty Rear Wiper Relay, Rear Wiper Relay harness is open or shorted, Rear Wiper 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: B1C77 indicates Rear Wiper Relay Circuit.
Common causes: Common causes include Faulty Rear Wiper Relay, Rear Wiper Relay harness is open or shorted, Rear Wiper 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 2,279

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 Aug 26, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B1C77 Description

The Body Control Module (BCM) monitors the Rear Wiper Relay. The BCM sets the OBDII code when the Rear Wiper Relay is not to factory specifications.

OBDII Code B1C77 - Rear Wiper Relay Circuit - AutoCodes.com — B1C77 Code - Rear Wiper Relay Circuit

What does this mean?

What are the Possible Causes of the DTC B1C77?

Faulty Rear Wiper Relay
Rear Wiper Relay harness is open or shorted
Rear Wiper Relay circuit poor electrical connection

How to Fix the DTC B1C77?

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 does this mean?

Code Tech Notes

B1C77:11 Rear Wiper Relay Circuit Short To Ground
B1C77:13 Rear Wiper Relay Circuit Open
B1C77:19 Rear Wiper Relay Circuit Current Above Threshold

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1C77 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 B1C77 code?

Need more information on how to fix the B1C77 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1C77 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1C77 Ford — Rear Wiper Relay Circuit
B1C77 Lincoln — Rear Wiper Relay Circuit
B1C77 Mercury — Rear Wiper Relay Circuit

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 B1C77 Code

1. What are common symptoms of OBDII code B1C77 (Rear Wiper Relay Circuit)?

The common symptoms of OBDII code B1C77 include the rear wiper not functioning properly or not working at all.

2. What are the possible causes of OBDII code B1C77 (Rear Wiper Relay Circuit)?

Possible causes of OBDII code B1C77 include a faulty rear wiper relay, damaged wiring or connectors in the rear wiper circuit, or a malfunctioning rear wiper motor.

3. How can I diagnose OBDII code B1C77 (Rear Wiper Relay Circuit)?

Diagnosing OBDII code B1C77 involves inspecting the rear wiper relay, checking the wiring and connectors in the rear wiper circuit for damage, and testing the rear wiper motor for proper functionality.

4. Can I still drive my vehicle with OBDII code B1C77 (Rear Wiper Relay Circuit)?

It is generally safe to drive your vehicle with OBDII code B1C77, but it is essential to address the issue promptly to ensure the rear wiper functions correctly, especially in adverse weather conditions.

5. How do I repair OBDII code B1C77 (Rear Wiper Relay Circuit)?

Repairing OBDII code B1C77 involves replacing the faulty rear wiper relay, repairing or replacing damaged wiring or connectors in the rear wiper circuit, or replacing the rear wiper motor if necessary.

6. Can weather conditions affect OBDII code B1C77 (Rear Wiper Relay Circuit)?

Extreme weather conditions, such as heavy rain or snow, can potentially exacerbate issues related to OBDII code B1C77 by putting additional strain on the rear wiper system.

7. How long does it take to repair OBDII code B1C77 (Rear Wiper Relay Circuit)?

The time it takes to repair OBDII code B1C77 varies depending on the specific issue, but it typically takes anywhere from 30 minutes to a few hours to diagnose and fix the problem.

8. Is OBDII code B1C77 (Rear Wiper Relay Circuit) a common issue in vehicles?

OBDII code B1C77 is a relatively common issue in vehicles with rear wipers, especially in older vehicles or those exposed to harsh environmental conditions.

9. Can I reset OBDII code B1C77 (Rear Wiper Relay Circuit) by disconnecting the battery?

Disconnecting the battery may clear the code temporarily, but it is not a recommended solution. It is best to diagnose the root cause of the issue and address it accordingly to prevent the code from reoccurring.

10. Does OBDII code B1C77 (Rear Wiper Relay Circuit) affect vehicle safety?

While OBDII code B1C77 may not directly impact the safety of driving the vehicle, having a malfunctioning rear wiper can compromise visibility, especially during adverse weather conditions, making it important to address the issue promptly.