AutoCodes – Generic – B1857

B1857 Code - Climate Control On/Off Switch Circuit Failure

Quick Answer

The Body Control Module (BCM) monitors the Climate Control On/Off Switch. Common causes include Faulty Climate Control On/Off Switch, Climate Control On/Off Switch harness is open or shorted, Climate Control On/Off 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: B1857 indicates Climate Control On/Off Switch Circuit Failure.
Common causes: Common causes include Faulty Climate Control On/Off Switch, Climate Control On/Off Switch harness is open or shorted, Climate Control On/Off 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 3,758

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 Jul 07, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code B1857 Description

The Body Control Module (BCM) monitors the Climate Control On/Off Switch. The BCM sets the OBDII code when the Climate Control On/Off Switch is not to factory specifications.

OBDII Code B1857 - Climate Control On/Off Switch Circuit Failure - AutoCodes.com — B1857 Code - Climate Control On/Off Switch Circuit Failure

What does this mean?

What are the Possible Causes of the DTC B1857?

Faulty Climate Control On/Off Switch
Climate Control On/Off Switch harness is open or shorted
Climate Control On/Off Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1857?

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 B1857 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 B1857 code?

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Need Help with the Code?

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Information for Specific Makes

B1857 Lexus — Short To Ground In Rear Side Squib Left Circuit
B1857 Scion — Short To Ground In Rear Side Squib Left Circuit
B1857 Toyota — Short To Ground In Rear Side Squib Left 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.