Overview
The ZF 4644.125.400 INDUCTIVE SENSOR is a critical electronic component engineered for precise rotational speed and position monitoring within ZF WG-series automatic transmissions. This OEM genuine part, identified by SKU 4644.125.400, is mounted directly into the transmission housing to detect gear rotation and relay real-time data to the transmission control unit (TCU). By converting magnetic field changes into electrical signals, it ensures accurate shift timing and clutch engagement. This sensor is commonly installed in conjunction with the 4642101047 TRANSMISSION HOUSING and the 4642301207 TRANSMISSION HOUSING, forming the backbone of the transmission’s electronic feedback system.
Symptoms of Failure
- Erratic or delayed gear engagement: A failing inductive sensor sends intermittent signals, causing the TCU to misinterpret shaft speed, leading to harsh or delayed shifts.
- Transmission stuck in limp mode: When the sensor fails completely, the TCU defaults to a safe mode, limiting vehicle speed to protect internal components.
- Inaccurate speedometer or tachometer readings: Since the sensor provides input for vehicle speed calculation, a worn unit often produces fluctuating or zero readings on the dashboard.
- Intermittent warning lights (check engine or transmission): The TCU logs fault codes for “implausible signal” or “sensor circuit malfunction,” often accompanied by reduced fuel efficiency.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (SKU) | 4644.125.400 |
| Type | Inductive Speed/Position Sensor |
| Housing Material | High-grade thermoset plastic with brass insert |
| Weight | Approx. 45 g (1.6 oz) |
| Operating Voltage | 12–24 V DC |
| Output Signal | Square wave (frequency proportional to speed) |
| OEM Reference | ZF 4644.125.400 |
| Thread Size | M12 x 1.5 |
| Protection Rating | IP67 (sealed against oil and dust) |
Compatibility
This OEM inductive sensor is specifically designed for ZF WG-series transmissions, including the WG100, WG150, WG180, WG200, and WG201 models. It is a direct replacement for the original sensor mounted in the transmission housing. When replacing this sensor, technicians often also inspect the 0730365067 TYPE PLATE for correct identification and the 0631311009 GROOVED STUD for secure mounting. The sensor fits both standard and heavy-duty variants of these WG series transmissions.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4642101047 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 4642301207 | TRANSMISSION HOUSING | Secondary housing component for sensor mounting |
| 0730365067 | TYPE PLATE | Identification plate for transmission model |
| 0631311009 | GROOVED STUD | Fastener for securing sensor bracket |
| 4642301168 | SCREEN SHEET | Oil filter screen for transmission sump |
| 4642301169 | SCREEN SHEET | Fine mesh filter for hydraulic circuit |
| 0636100621 | HEXAGON SCREW | Mounting bolt for housing assembly |
| 4642301186 | SCREEN SHEET | Additional oil strainer for high-flow systems |
| 4644106300 | SHIFT SYSTEM | Hydraulic shift actuator assembly |
| 4644306500 | COVER PLATE | Protective cover for sensor access port |
