Bosch EHR Control Unit 4 Agricultural Machine Lifter

Typical defects: The lifter does not work or moves irregularly. Fault warning lights illuminated on the instrument cluster. Difficulty controlling the oscillator.

The 0538201009 is a Bosch control unit for EHR (Electronic Hitch Regulation), i.e. the electro-hydraulic control of the three-point hitch on tractors. It belongs to the EHR4 analog generation (“Hitch-Tronic” Bosch/Rexroth): it manages height/position, controlled draft (force), limiters and safety functions of the rear hitch, interfacing with position and force sensors and driving the hydraulic lift/lower solenoid valves. Technical specifications - Family: EHR4 - Power supply: 12/24 V DC depending on the machine configuration (12 V systems are very common in agricultural applications). - Inputs: - Arm position sensor (angular potentiometer of the lift). - Force/draft sensors (torque pins/bolts or torsion bar). - Operator controls (setpoint knobs/sliders, raise/lower buttons, limiter switches). - Safety interlocks (clutch/pedal, speed, various switches, depending on the tractor manufacturer). - Outputs: - Proportional/on-off solenoid valves of the EHR distributor (lift/lower, dump). - Diagnostic LEDs/indicators and dashboard lamps. DIPA can intervene to overhaul these modules thanks to its experience and expertise. Functions - Position control: maintains the set arm height with error compensation. - Draft control (force): modulates implement depth based on the force detected on the linkage. - Mixed strategies: position + draft with variable weighting. - Limiters: minimum/maximum travel, lowering speed, shock damping. - Safeties: stop on out-of-range sensors or command inconsistencies. - Self-test/LED: status and fault indications for quick diagnosis. Application models - Massey Ferguson tractors - Same Deutz tractors Typical faults - The hitch does not operate or moves irregularly. - Fault lights illuminated on the instrument panel. - Difficulty controlling oscillation. Final conclusions The Bosch 0538201009 (EHR4) is a robust and widely used control unit for hitch control. DIPA has a wide range of spare parts dedicated to the agricultural sector: from vehicle-related parts to those for auxiliary equipment. It also offers refurbished components with like-new performance that allow cost savings on replacements while contributing to environmental protection through the circular economy. If the spare part you need is not available, don’t worry: DIPA can refurbish your part on demand, restoring full functionality and safety in a short time.