MS561 PRO – A Universal Tool for EPS Diagnostics and Repair

Modern electric power steering (EPS) systems are sophisticated and high-tech systems that significantly improve driving comfort and safety. With advantages such as cost-effectiveness, responsiveness and the ability to integrate with driver assistance systems, they are becoming a standard in the automotive industry and are playing a key role in the development of autonomous vehicles.

In recent years, power steering repair service has become one of the most sought-after services among car owners. This is due to several factors:

• increase in the number of cars equipped with EPS;
• increased driver awareness of the possibility of quality ESC repair;
• economic benefits of repair

Qualitative repair electric power steering is first of all provided by using modern equipment for diagnostics of malfunctions. Tester MS561 PRO – is an advanced and universal tool for diagnostics and repair of electric power steering, which is capable of diagnosing EPS units of more than 4000 car models.

Why is the MS561 PRO a versatile tool for EMS diagnostics?"

To determine the cause of an electric power steering fault you need to switch the power steering on separately from the electric vehicle system. This is the biggest challenge because EPS uses different technologies to transmit data and control the system.

One of the most common technologies for data transmission in a car is the CAN bus. Nowadays, it is becoming increasingly common to find steering racks that are controlled via two independent CAN buses. This is the case, for example, with electric power steering systems on vehicles such as:

All of the following.

• Chevrolet Volt (2015 – 2018)
• Chevrolet Cruze USA (2015 –)
• Chevrolet Suburban (2020-2022)
• OpelOpelAstra K (2015 – 2019)
• Tesla Model X (2016-)
• Tesla Model 3 5YJ3 (17-)
• Jeep Grand Cherokee V (WL) (2021-)

The use of two CAN buses provides data redundancy, which makes the system more reliable, and also ensures the stable operation of information-intensive systems such as adaptive cruise control and autopilot.

A new data bus – CAN-FD, which offers higher data rates (up to 8 Mbit/s) and allows more data to be transferred in a single message, is being used in cars of recent years. Some VAG Group vehicles use the FlexRay data bus. The FlexRay bus differs from the others in the differential way of data transmission, which takes place according to a set schedule, thus ensuring fast and highly reliable data transmission. And there are also electric power steering systems that are controlled by unique special signals.

The MS561 PRO tester is capable of running EPS with any of the above methods of data transmission and system control. To do this, the EPS must be connected with the appropriate special cable that the tester indicates. Instead of the special cable you can connect to the unit with the universal cable MS-35670, the connection diagram of the universal cable to the EPS unit will also be shown by the tester. However, it is impossible to connect all units with the universal cable, there are units for which special cables must be used. For example, if the ESC is controlled via FlexRay bus, then to connect such units you need to use special cable MS39000. 

MS39000 cable for connecting the ESC with FlexRay bus
The MS561 PRO tester provides a lot of useful information during the EPS diagnostic process:

• normal (correct) current consumption, which the tested unit should have;
• data packets received from the machine and their decoding;
• list of non-critical errors

In the repair process, the MS561 PRO tester provides the following useful features:

• Diagnosis of torque sensors separate from the rack;
• Programming the VIN in the rack control unit;
• Resetting the rack's binding to the car.