When the fault isn't where it seems: troubleshooting the electronics on a street sweeper

On municipal cleaning vehicles, a malfunction can have very different causes. What appears to be the faulty component is often only the consequence of a problem originating somewhere else.

This was the case of a street sweeper that arrived at TECAM Service with its sweeping system completely out of operation.

The request

The customer reported that the sweeping system was not working, preventing the vehicle from carrying out its normal operations.

The first inspection focused on the electrical system and control circuits. Initial checks identified a fault in the pneumatic system's solenoid valves.

After replacing the valves, the sweeping unit started working again, but only partially. It was clear that the root cause of the problem had not yet been fully identified.

The solution

The TECAM Service team then carried out an in-depth troubleshooting process, inspecting the entire electrical wiring harness, from the cab control panel to the ECU compartment. The investigation was performed using the manufacturer's technical documentation and by checking each electrical signal throughout the circuit.

This detailed analysis eventually led to the actual cause of the malfunction: the main Electronic Control Unit (ECU).

Once removed, the ECU showed clear signs of oxidation, which had caused an internal short circuit and prevented the system from operating correctly.

The result

The presence of corrosion and an internal short circuit strongly suggests that the ECU is the root cause of the malfunction. However, this can only be confirmed after the control unit has been replaced and the machine has successfully completed functional testing.

This case highlights how essential electronic diagnostics have become in the maintenance of street sweepers and other municipal cleaning vehicles. Identifying the true cause of a fault requires a systematic approach, the right diagnostic tools, and expertise across multiple disciplines, from electronic systems to pneumatic circuits.

Because the first component that stops working is not always the one that caused the problem.

Is your vehicle experiencing electronic faults or difficult-to-diagnose malfunctions? Contact TECAM Service. We investigate every issue thoroughly to identify the real cause and avoid unnecessary component replacements.