2023-2026 Jeep Compass Blindspot/ADAS Inoperative DTC B178F-15

Owners of 2023-2026 Jeep Compass vehicles might encounter issues with several advanced driver-assistance systems (ADAS) becoming inoperative. These include the Blindspot monitoring system, Automatic High Beams, Forward Collision Warning, and Lane Management features.

When these systems fail, technicians often find a specific Diagnostic Trouble Code (DTC) B178F-15 stored or active in the vehicle's computer. This code indicates a "Turn Signal Switch Circuit Short to Battery," pointing to a problem within the electrical system related to the turn signal switch.

Symptoms

If your 2023-2026 Jeep Compass is affected, you may notice the following systems are not functioning:

• Blindspot: The system designed to alert you to vehicles in your blind spots will be inactive.
• Automatic High Beams: The headlights will not automatically switch between high and low beams based on traffic conditions.
• Forward Collision Warning: The system that warns of potential frontal collisions will not provide alerts.
• Lane Management Inoperative: Features like LaneSense Lane Departure Warning or Lane Keep Assist will not operate.

These symptoms are typically accompanied by the presence of DTC B178F-15.

Fault Codes / DTCs

Technicians diagnosing this issue will likely find the following Diagnostic Trouble Code:

Code	Description	Module Affected
B178F-15	Turn Signal Switch Circuit Short to Battery	Various

This DTC B178F-15 indicates an electrical short circuit within the turn signal switch system, which can impact the functionality of other interconnected safety systems.

Diagnosis and Trigger Conditions

The presence of DTC B178F-15, specifically indicating a "Turn Signal Switch Circuit Short to Battery," is the primary diagnostic indicator for this problem. When this code is active or stored, it suggests an electrical fault within the turn signal switch circuit that prevents the related ADAS systems from operating correctly. The STAR Online Publication S2508000104 highlights this specific condition.

Important Warnings

Stellantis has issued a critical advisory regarding this issue. The STAR Online Publication S2508000104 states: "This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the appropriate course of action."

Furthermore, for the specific issue of the Jeep Compass B178F-15, it is explicitly stated that technicians "should not replace the Body Control Module (BCM), the BCM is not a factor causing this fault." This prevents unnecessary and costly repairs.

Repair Procedure Summary

For vehicles exhibiting the Jeep Compass B178F-15 fault, the recommended repair procedure, as outlined in STAR Online Publication S2508000104, focuses on the Steering Column Control Module (SCCM). Technicians are instructed to:

1. Avoid BCM Replacement: Do not replace the Body Control Module (BCM), as it has been identified as not being the root cause of this particular fault.
2. Follow Diagnostic Tests: Perform the specific diagnostic tests for DTC B178F-15.
3. Replace SCCM: Only replace the Steering Column Control Module (SCCM) if the diagnostic tests confirm it is faulty and necessary to resolve the issue.

This targeted approach ensures that the correct component, the SCCM, is addressed, which is responsible for processing signals from the turn signal switch and can impact the functionality of the affected ADAS systems.

Owner Action

If your 2023-2026 Jeep Compass is experiencing inoperative Blindspot, Automatic High Beams, Forward Collision Warning, or Lane Management systems, and you suspect a DTC B178F-15, it is advisable to visit an authorized Jeep service center. Inform the technician about the specific symptoms and mention the potential relevance of STAR Online Publication S2508000104 and DTC B178F-15. This will help them diagnose the issue accurately and efficiently, focusing on the Steering Column Control Module (SCCM) as the likely culprit.

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Source: NHTSA ID: 11026633