B1C5E13 - B1C5E13 Right Charging Port Lighting Lamp Driver Circuit Open Circuit

B1C5E13 Right Charging Port Lamp Drive Circuit Open Circuit Fault

Fault Depth Definition

B1C5E13 Diagnostic Trouble Code (DTC) specifically points to high-level electrical architecture issues in the EV body domain control system for the lighting function in the right charging port area. This DTC is identified as "Right Charging Port Lamp Drive Circuit Open," technically representing an open circuit (Open Circuit). It indicates that when the control unit outputs a drive command to the load end, it fails to detect the expected closed current loop or feedback signal. Electrically, this represents a non-physical impedance interruption between the Controller's output pin and the Actuator (lamp), i.e., an Open Circuit state. The generation of this DTC means that the Right Domain Controller identified compromised circuit integrity during load monitoring or drive testing, thereby judging the power circuit to be disconnected. This fault affects not only the visual guidance function inside the charging port but also reflects a failure of the communication link between the chassis harness and the body control module at specific nodes, belonging to key indication system anomalies in the vehicle electronic architecture.

Common Fault Symptoms

During driving or maintenance, owners may identify the existence of this fault through perceivable physical feedback or digital system prompts:

• Charging port lamp does not illuminate
• Cannot obtain expected internal environmental light guidance when opening the charging cover
• Vehicle Diagnostic Interface (OBD) reads specific body electrical fault storage information
• Dashboard may display corresponding maintenance prompts or light up indicator lights, depending on configuration

Core Fault Cause Analysis

Based on the underlying logic and data characteristics of DTC B1C5E13, this fault is triggered primarily by hardware or logical anomalies in the following three dimensions:

• Hardware Component (Actuator End): Physical failure of the charging port lamp itself. This could be internal damage to the LED light source unit, LED beads aging and unable to conduct, or circuit node fracture caused by mechanical stress from the fixture bracket.
• Wiring/Connector (Connection Medium): Harness or connector faults. Specifically includes physical wear on power wiring near the right charging port causing conductor breakage, or excessive contact resistance leading to an open circuit due to corrosion, oxidation, and looseness of connector terminals, preventing current from forming an effective loop.
• Controller (Logic Operation End): Right Domain Controller fault. The drive level circuit inside the control unit (e.g., power transistors) may suffer open failure, or internal detection circuits fail to correctly identify external states, leading the system to mistakenly judge a drive circuit open and record this DTC.

Technical Monitoring and Trigger Logic

Automotive electronic control systems monitor and determine the right charging port lighting loop in real-time through the following mechanisms:

• Monitoring Target: System continuously monitors current flow at the load end and voltage feedback status of the driver output node, focusing on detecting "High Impedance Open" characteristics.
• Numerical Range and Thresholds: Although specific internal algorithm parameters are confidential, the trigger logic is based on load response after drive signal emission. When the control unit applies a drive voltage (such as $12V$ system level), if the measured loop current is close to zero or falls within a preset extremely high resistance range, the open circuit condition is judged to be established.
• Specific Conditions: Fault determination specific conditions typically occur during vehicle power-on self-check phases, or at the instant a user manually opens the charging port cover and triggers the lighting function. At this time, the domain controller enters dynamic monitoring mode; once it continuously detects signal characteristics that cannot conduct drive current, it records B1C5E13 DTC and may light up corresponding fault indicator lights.