A customer brought their 2013 Volvo into the shop, concerned about a very noticeable lack of throttle response. The malfunction indicator light (MIL) was off.
Case details
The technician connected a scan tool and checked for diagnostic trouble codes (DTCs). There were no DTCs, but he found that there was no communication on the high-speed CAN bus. at this point, he called ALLDATA Tech-Assist for some time-saving diagnostic advice.
The Tech-Assist consultant noted that there were several modules that communicated on the high-speed CAN bus and suggested disconnecting each module one at a time until communication returned. He recommended starting with the power steering module and the rear differential control module since the Tech-Assist team has seen numerous failures of these modules.
The technician started disconnecting modules as suggested and found that communication came back when the rear differential control module was disconnected. The power and grounds to the module were good.
Confirmed repair
After replacing the rear differential control module, the technician went on a test drive. The vehicle’s acceleration and performance were restored to normal. Fixed!
