Yesterday we inspected a Paccar truck with a serious problem. Several internal components had already been replaced because it was losing power and the truck wasn't accelerating properly. A preliminary diagnosis suggested the turbo wasn't working correctly, as the sound was purely engine noise. However, to confirm the problem, we connected Inpronic's AI Suite. This revealed that the turbo's boost value, displayed in hexadecimal frames, wasn't changing when accelerating; it was frozen and exhibiting intermittent, momentary spikes in performance.
We checked the truck's fault codes and identified a "Voltage Above Normal" fault, indicating a short circuit to positive. The source address of the problem was identified, so we went to the CanBus network of the module with SA 49 and found a problem in the wiring from instrument cluster 2 to the cabin, which was triggering the electrical harness failure. Once this was fixed, the engine was restarted and the CanBus data returned to normal. The turbo values resumed communicating correctly, and the problem was resolved.
