P1AD900 - P1AD900 Charging Port Temperature Sampling Point Anomaly

P1AD900 Charging Port Temperature Sampling Point Abnormality Fault Deep Analysis

Fault Definition Deep Dive

P1AD900 fault code indicates activation of the thermal safety monitoring mechanism in the on-board power system under AC charging conditions for the vehicle. This fault definition involves abnormal communication or monitoring failure between the Controller and Battery Management System (BMS) regarding the thermal management feedback loop. Specifically, this sampling point is responsible for collecting real-time physical environmental temperature data connected to the AC charging port, transmitting it to the central diagnostic interface in the form of pulse signals or digital signals. When the control system detects that the data flow in this feedback loop does not match the expected safety model, it determines a sampling point abnormality. The core function of this fault code is to prevent electrical safety accidents caused by overheating of the charging port and ensure that the thermal management system can respond in real time based on accurate temperature data during the charging dynamics process.

Common Fault Symptoms

When the system detects abnormalities related to P1AD900 signals, the vehicle's control logic will start protection strategies, leading car owners to perceive the following specific phenomena:

• Charging Power Limitation: The whole vehicle control system actively reduces AC charging current output, manifested as significantly reduced charging speed or inability to enter high-power charging mode.
• Charging Status Interruption: During charging, unexpected pauses may occur, fault warning lights on the charging port indicator light up, or the system prompts charging termination information.
• Dashboard Display Anomalies: Warning icons related to battery state of charge management or charging port temperature may appear on the dashboard (such as plug icon flashing), indicating charging efficiency is not up to expectations.
• System Protective Lockout: In serious cases, the on-board power assembly may trigger overheating protection logic, prohibiting the vehicle from restarting the charging process until the fault code is cleared.

Core Fault Cause Analysis

Based on system architecture analysis, the generation of P1AD900 faults can be classified into potential failures in the following three technical dimensions:

• Hardware Component Failure: The most direct physical cause is the performance degradation or internal damage of the AC charging port temperature sensor itself, leading to an inability to output accurate resistance or voltage value feedback signals. As the sensing terminal of the thermal management link, its own accuracy deviation will directly trigger protection logic.
• Wiring and Connector Faults: The harness connecting between the sensor and control unit may appear worn, insulation layer damaged or short circuit; at the same time, connectors (connectors) due to oxidation, looseness or pin retreat causing contact resistance too large, resulting in distorted transmitted signals. Such physical connection problems will hinder normal temperature sampling data from reaching the controller.
• Controller Logic Operation Abnormality: Control chips inside the on-board power assembly may appear logic operation errors, unable to correctly parse sensor input; or Battery Management System (BMS) when performing fault judgment threshold calibration appears deviation. These electronic control unit level anomalies will cause the system to erroneously generate P1AD900 fault code after receiving normal signals.

Technical Monitoring & Trigger Logic

The setting mechanism of this fault code is based on strict real-time operating condition monitoring, its core logic follows the following technical parameter process:

• Monitoring Target: The system focuses on monitoring the stability and rationality of temperature sensor feedback values under vehicle AC charging status. Monitoring objects include the analog voltage output value of the sensor or temperature variables in digital communication messages.
• Trigger Condition Definition: The specific operating condition limit for fault determination is "Vehicle AC Charging Status" (Vehicle AC Charging Status). Only when high voltage connection status is detected and energy transmission is ongoing, the system activates high-frequency scanning for this sampling point.
• Judgment Logic and Value Range: When the control unit receives abnormal temperature sensor value signals during charging, the system will judge sampling data exceeds preset safety thresholds or appears fluctuating. Once confirmed received signal values do not conform to normal physical model (such as $T_{signal} > T_{max}$ or $V_{sensor}$ deviates from reference voltage), the system immediately generates fault code P1AD900 and records freeze frame data, ensuring thermal management system intervention response. This logic aims to prevent safety hazards caused by charging port overheating through dynamic monitoring, ensuring overall vehicle electrical safety.