C117498 - C117498 Motor Driver Chip Temperature Abnormal

C117498 Motor Driver Chip Temperature Anomaly: Failure Mechanism and System Interaction Analysis

Fault Depth Definition

C117498 (Motor Driver Chip Temperature Anomaly) is a key diagnostic fault code within the Vehicle Electronic Parking Brake System (EPB), centrally pointing to the internal thermal management monitoring mechanism of the control unit. In this automotive electronic architecture, the motor driver chip serves as the executive hub converting electrical energy into mechanical energy, responsible for real-time feedback of the motor's physical position and rotational speed, while maintaining stable operation of the drive circuit. This fault code does not simply reflect a single sensor reading, but signifies that the internal electronic drive Integrated Circuit (IC) within the Rear Domain Controller has detected temperature parameters exceeding preset safety thermal management thresholds during operation. The system continuously evaluates the matching relationship between the chip's heat dissipation capability and load requirements through monitoring algorithms integrated within the control unit; once abnormal temperature fluctuations are detected, it triggers the C117498 fault signal, indicating that the drive protection mechanism has been activated or hardware integrity is questionable.

Common Fault Symptoms

Based on system logic judgment and vehicle feedback, owners and diagnostic terminals may observe the following specific manifestations:

• EPB system failure, resulting in the inability to maintain a stationary state when parked on slopes;
• Electronic parking brake warning light on the dashboard illuminates or flashes, indicating system communication or functional anomalies;
• The EPB control unit enters a fault protection mode, prohibiting motor extend/retract actions;
• Relevant vehicle network diagnostic tools read stored permanent or intermittent fault code records for C117498.

Core Fault Cause Analysis

According to the fault source information provided by original data, this anomaly is primarily classified as an internal fault in the Controller (Logic Computation and Hardware Components) dimension, with specific analysis as follows:

• Rear Domain Controller Hardware Failure: The root cause clearly points to "Rear Domain Controller Failure," meaning physical circuits, temperature sensors, or the drive chip itself within the control unit have suffered hardware damage. This belongs to core hardware level failure, causing it to be unable to correctly calculate or monitor chip temperature rise.
• Thermal Management Logic Computation Error: The internal software algorithm of the controller deviates when evaluating chip temperature, misjudging the current thermal environmental state, triggering fault records before reaching extreme conditions.
• Drive Power and Line Support Issues: Although primarily classified as controller failure, motor drive chips have extremely high requirements for power supply stability; if the power module within the Rear Domain Controller is unstable (part of hardware components), it may cause abnormal operation of local temperature monitoring circuits, leading to falsely elevated temperature readings or signal distortion.

Technical Monitoring and Trigger Logic

The system's diagnostic logic follows specific operating conditions; the control unit will only judge and record this fault code when the following prerequisites are met:

• Trigger Conditions: Ignition switch in ON position, and EPB switch actuation. System monitors in real-time only during ignition power activation and when driver or system actively requests parking brake operation (such as tightening handbrake, releasing handbrake) dynamic processes.
• Monitoring Target: Core monitoring object is the working temperature of the motor driver chip (Chip Junction Temperature). In dynamic monitoring, the control unit collects thermistor data on the chip package surface in real-time or infers temperature values via current estimation models.
• Judgment Logic: When executing EPB function instructions, if the detected chip temperature value continuously exceeds the system-set internal safety threshold, or there is a sharp temperature gradient change in a short time, the system will immediately interrupt current drive operations, store fault code C117498, and illuminate relevant instrument panel warning lights to ensure vehicle parking safety is not affected.