0DE927711B

1. Multi-Level Fault Protection and Heat Management

Targeting the reliability requirements of wet DSG, the TCU is equipped with a four-level fault diagnosis and protection system (diagnosis frequency of 150 Hz) and a dedicated clutch heat management module, which monitors key components (dual clutches, hydraulic valve group, oil temperature sensor, CAN communication) in real time to avoid major failures caused by overheating or pressure anomalies.

Level 1 (Minor Fault): For slight clutch slip (slip rate < 2%) or minor oil pressure deviation (±0.03 MPa), the TCU adjusts the clutch pressure in real time—for example, increasing Clutch 1 pressure by 0.05 MPa to compensate for slip, ensuring normal driving without activating the fault light;

Level 2 (Moderate Fault): When the clutch temperature exceeds 130℃ or the solenoid valve current deviates by 15%, the TCU switches to "heat protection mode": limits the maximum speed to 110 km/h, disables sport mode, and increases the oil pump speed to maximum, reducing clutch load;

Level 3 (Severe Fault): In case of single clutch failure (e.g., Clutch 1 stuck) or hydraulic pressure loss, the TCU activates "single-clutch operation mode": uses only the normal clutch to control odd/even gears (e.g., using Clutch 2 to drive 2nd/4th/6th gears), locks the maximum speed to 90 km/h, and lights up the yellow fault warning light;

Level 4 (Emergency Fault): When both clutches fail or TCU internal short circuit is detected, the TCU immediately cuts off the hydraulic pressure supply, locks the transmission in neutral, sends an emergency signal to the ESC system, and reduces the engine torque to idle level (800 rpm) to prevent vehicle out of control.

The TCU supports Volkswagen’s extended OBD-II fault codes, with common ones including:

P0730: Gear ratio error (usually caused by clutch slip);

P0868: Transmission fluid pressure too low (hydraulic pump failure or oil leakage);

P174B: Clutch temperature sensor fault;

P178B: Dual-clutch coordination error.

Using Volkswagen’s original diagnostic tool (VAS 6154) or compatible third-party tools (e.g., Launch X431 Pro), maintenance personnel can read detailed fault logs (including clutch temperature and pressure at the time of fault) and complete "clutch adaptation" to restore performance—fault location time is within 15 minutes, 50% faster than universal TCUs.

2. Hybrid Power Synergy Control (for PHEV Models)

For plug-in hybrid models equipped with 0DE927711B TCU, the unit adds a hybrid power coordination module to realize seamless switching between pure electric, hybrid, and regenerative braking modes, matching the 1.4T engine + 85 kW electric motor system.

Pure Electric Mode (SOC > 70%): The TCU cuts off the engine connection, maintains the engine clutch pressure at 0.08 MPa (disengaged), and controls the electric motor to drive the vehicle via Clutch 2—supporting a pure electric range of up to 60 km for the Volkswagen Passat GTE;

Hybrid Mode (SOC 30%-70%): The TCU coordinates engine-motor torque distribution—at low speeds (< 60 km/h), the motor provides 70% of the torque to reduce engine idling loss; at high speeds (> 100 km/h), the engine takes over the main driving task, and the motor enters power generation mode;

Regenerative Braking: When braking, the TCU adjusts the electric motor to reverse torque (up to 200 N·m) and coordinates the clutch to disengage, ensuring the motor efficiently recovers energy—recovery rate up to 80%, which is 15% higher than that of mild hybrid systems.