AutoCodes – Chrysler – B178E Chrysler

B178E Chrysler Code - Headlamp Switch Input Circuit Short to Ground

Quick Answer

The Body Control Module (BCM) receives an input voltage from the headlamp switch. Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp 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: B178E Chrysler indicates Headlamp Switch Input Circuit Short to Ground.
Common causes: Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp 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 39

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 Nov 05, 2025

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code B178E Chrysler Description

The Body Control Module (BCM) receives an input voltage from the headlamp switch. The BCM monitors the headlamp switch voltage and controls the exterior lighting functions based on the switch input. For additional information on Headlamp Switch operation. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a low condition on the Headlamp Switch MUX circuit.

OBDII Code B178E Chrysler - Headlamp Switch Input Circuit Short to Ground - AutoCodes.com — B178E Chrysler Code - Headlamp Switch Input Circuit Short to Ground

What does this mean?

What are the Possible Causes of the DTC B178E Chrysler?

Faulty Headlamp Switch
Headlamp Switch harness is open or shorted
Headlamp Switch circuit poor electrical connection
Faulty Diagnostic Trouble Code (DTC)

How to Fix the DTC B178E Chrysler?

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 B178E Chrysler 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.