We recently received feedback from a customer who had encountered an issue while using our M3-A motorcycle diagnostic tool on their 2021 Yamaha NMAX 155 V2. The customer shared the following:
Question:
"I bought the M3-A recently. My unit is a 2021 Yamaha NMAX 155 V2. The scanner only reads ABS and Voltage. However, I get a problem when entering ECM; it says 'communication error.' The cable connection is fine, and I’ve even tried updating to the latest firmware, but the problem persists."
After a quick discussion with the customer, we discovered that they were using the 4-pin Yamaha connector to interface with the diagnostic tool. This led us to identify the root cause of the issue.
We explained that on the Yamaha NMAX, the 4-pin connector is used specifically for the ABS system, while the ECU (Engine Control Unit) requires a 3-pin connector. This small but crucial detail was what caused the communication error when trying to access the ECM.
Once the customer switched to the correct 3-pin connector for the ECU, the issue was resolved successfully. The scanner was then able to communicate with the ECM without any further problems.
We’re sharing this case to help everyone who may encounter a similar situation in the future. If you face a similar issue with the M3-A and a Yamaha NMAX, simply check the connector you're using for the ECU and make sure it’s the 3-pin connector—this should resolve the problem.
We appreciate our customers’ feedback, as it helps us improve the user experience for everyone. Thank you for choosing the M3-A, and we’re always here to support you with any diagnostic needs.