Merlo Tech Talk: Tracing for Continuity: CAN-BusApplied Machinery Sales
CAN-Bus stands for Controller Area Network and consists of two electrical wires called CAN_Low and CAN_High. These wires allow microcontrollers and devices to communicate with each other.
When a Merlo throws a fault, it is good technician practice to be methodical in tracing the fault to its source. Usually, first practice is to check power and ground. From there, the next course of action may be to check the CAN-Bus connections. Found in every piece of equipment that has computer and sensors, CAN-BUS networks on average runs on 6 volts (three up and three down).
Merlo runs 5V total. Each line continuously send 2.5V, or volts that will add up to 5V. CAN-Bus lines are yellow and green twisted together.
For the sake of this conversation, let’s use the following example: the length sensor is not working.
A technician will log into the onboard diagnostics (April 2021 Tech Talk here) to see which system or sensor is throwing the fault.
Once the “where” is found, a technician will start with the basics and drill down from there.
Reminder: the circuit panel for many Merlo’s is found behind the seat.
Disgengage the ‘connector’
Using a Multi-meter first check two things: power and ground.
If those numbers are correct:
- Put the negative meter line on the ground
- Check each CAN-Bus line for voltage ranging around 2.5V.
Remember: Merlo CAN-Bus reads at 5V.
The reading on the individual lines will fluctuate depending on if its UP or DOWN.
For Panoramic Merlo models (cabs without the white swoosh on the side) in lieu of the on-board diagnostics, technicians will need to use the Merlo Black Box to trace the fault.