Check wiring

How individual components and assemblies of the Stromer interact with the System Integration Test (SIT) test is available here.

In addition to the components, their cabling is also a source of faults. Here you can find:

• Corroded or loose plug connections
• Crushed, torn or chafed cables
• Unplugged connectors

Due to the Inframe cabling used by the majority of Stromers, it is not always easy to check. I have attached a list showing possible sources of error in connection with the cabling.

TMM sensor > Plug connection / cable

Older models had a continuous cable from the sensor to the Omni. Newer models use a plug-in connection in the right-hand chain stay.

If there are problems with the support, the TMM sensor is often targeted. However, it is not the first source of errors. Nevertheless, it is worth looking at the wiring. Incorrect installation can also lead to faults. In this P178, the cable was crushed during installation.

Check the plug connection and/or remove the sensor and check the cable. The rear wheel must be removed for this.

Motor cable on the left chain stay

On older models, three cables led to the motor (motor cable / Hall and temperature sensor), with the Hall and temperature sensor becoming one again just before the motor. There was also a programming connection for hub motors with an integrated controller.

In newer models, the wiring was reduced to a Higo screw connection, which includes all connections to the motor (3-phase motor cable, Hall and temperature sensors). The cable runs close to the brake disk. It must be held in position with a cable tie.

In the event of support problems, check the screw connection(s) of the motor cable(s) for tightness and moisture. Also check the cable for damage (caused by the brake disk) and the presence of a cable tie.

On the ST2 (2016) / ST2S, the motor connector is installed directly on the motor flange. With this type, it is cable breaks or mechanical problems that lead to faults in the support. A repair is difficult, usually the cable has to be replaced.

Check the cables for breaks and the flange for damage.

Motor cable in the pedal bearing area

On all models, the three motor phase cables lead to the motor via the bottom bracket area. All models with a chain before 2019 were affected by a 'design flaw'. The motor cable plug connections to the controller were not sealed. In 2018, Stromer introduced a Work instruction for all models of the ST2 platform (ST1x / ST2 / ST2S), which describes how the motor cables can be subsequently sealed.

If you have an older Stromer with a chain, check the motor cables in the bottom bracket area and seal the plug connections with shrink tubing if necessary.

Wicket Cable

The wicket cable connects the battery output to the controller and can be found in the battery compartment/bottom bracket area. It connects the 48 V (or 36 V) on-board voltage, the 12 V auxiliary voltage and the CAN bus connection of the battery with the on-board electrical system. Due to overloading of the 48 V line and sometimes also moisture in the bottom bracket area, the plug connection (SAE plug) can corrode, burn through and/or the cables can cause short circuits.

If errors occur in the support, check the wicket cable. In many models, the battery compartment (ST3 / ST5...) must be removed for this purpose. In newer models, the vulnerable SAE plug connection has been replaced by RC or T-Dean connections.

Distribution Board (ST1, ST2-Belt, ST7)

The ST1 and ST2-Belt, ST7 models have the controller installed in the down tube. The connection to the bike electrics is established by means of a distribution board. Moisture (condensation) in the battery compartment sometimes leads to corrosion of the distribution board. This results in malfunctions.

Check the DB board. Remove any corrosion or replace the board. Stromer has now made improvements and newer model years are better protected against moisture.

Distribution Board ST5 (first batches), ST2

The first batches of the ST5 had a distribution board in the stem. Moisture and water ingress led to corrosion and contact problems and corresponding faults. Older ST2s with the distribution board mounted at the top of the battery compartment had the same problem.

Stromer offers an upgrade for the ST5 in which the distribution in the stem is removed and replaced by new cabling.

Ask your dealer about conversion or order the Cable kit and do it yourself. Here you will find the corresponding Work instruction.

Battery socket, charging socket, battery compartment socket

Stromer uses the magnetic Rosenberger connection for detachable connections. The detachable connections include the charger plug, the charging socket in the Stromer, the battery base and the battery socket in the battery compartment at the bottom. The Rosenberger plug connection is practical and, thanks to its magnetic properties, is also reliable when driving. However, it also tends to corrode when exposed to moisture in combination with current flow. Due to its magnetic properties, it also attracts the smallest metal particles, which can lead to leakage currents or short circuits.

Clean the contacts/socket with a lint-free cloth or compressed air. Do not use contact sprays/grease or the 'all-purpose weapon' WD40 Multifunction Smart Straw.

Brake lever contacts

The brake levers have a built-in reed switch that controls the brake light and triggers recuperation. The right-hand brake lever is also required for accessing the service menu. On models with Magura brakes, the brake cables still have a plug connection between the brake lever and the frame.

Problems with the reed switches are rare, but the plug connection on the Magura brakes is a source of faults.

Checking the reed switches and plug connections is simple: if the brake light comes on, the reed contacts and cables are OK.

Torn cables

The wiring of the Stromer is inframe and is sometimes very tight. The turning movement of the handlebars in particular places mechanical stress on the wiring. The fault pattern is rare, but it can happen that a cable breaks or is crushed due to incorrect installation.

Omni connection board

All information comes together in the Omni, as do all the cables from the peripheral devices.

In this example, there were problems with the TMM sensor. The reason was an unplugged TMM sensor cable. During installation, care must be taken to ensure that the plugs engage properly in the socket.

In addition to loose plugs, there is also the problem of corrosion in the Omni, as with other plug connections. This is caused by water ingress and leads to contact problems and malfunctions.

The typical image of corroded plug connections is green-blue deposits.

If something is not working, it is worth checking the plug connections.

Omni Display - Water

Even the Omni is not immune to water ingress. It cannot be repaired and must be replaced.