ZF 4646.125.021 INDUCTIVE SENSOR for WG250 | OEM Genuine Part

Overview

The ZF 4646.125.021 INDUCTIVE SENSOR is a precision electronic component engineered specifically for the WG250 series transmission. This OEM genuine part monitors rotational speed and position of the output shaft within the gearbox, sending critical data to the transmission control unit (TCU) for precise shift timing and clutch modulation. Installed directly into the TRANSMISSION HOUSING, the sensor detects ferrous targets without physical contact, ensuring reliable operation in high-vibration environments. The SKU 4646.125.021 is the direct factory replacement for WG250 applications, guaranteeing exact fitment and signal integrity.

Symptoms of Failure

• Erratic gear engagement or harsh shifting – When the inductive sensor fails, the TCU loses accurate shaft speed data, causing delayed or abrupt clutch applications during upshifts and downshifts.
• Transmission stuck in limp mode – A faulty 4646.125.021 often triggers fault codes for missing or implausible speed signals, forcing the transmission into a reduced-power safety mode.
• Intermittent loss of torque converter lockup – Without proper sensor feedback, the torque converter clutch may fail to engage, leading to elevated fluid temperatures and reduced fuel economy.
• No start condition or engine crank without engagement – In severe cases, a dead sensor prevents the TCU from confirming shaft rotation, blocking starter interlock circuits.

Technical Specifications

Compatibility

While primarily designed for the WG250 series, this inductive sensor is also used in ZF WG180, WG200, and WG210 transmissions produced between 2008 and 2020. It replaces earlier part numbers 4646.125.010 and 4646.125.015. Always verify the sensor mounting boss in your HOUSING before installation. The sensor is paired with the COVER that protects the wiring harness connector, and is secured using a HEXAGON SCREW (M6 x 20 mm).

Related Components