July/August 2021

BY Damien Coleman, Product Manager/ EBI Specialist at Snap-on T his 2017 Volvo XC60 with a two-litre common rail diesel injection engine (D4204T14) had multiple electrical failures reported by the owner. These were all relating to the Body electrical system. The faults were intermittent in nature. When the issue was present the following sub-systems failed to operate: Remote Keyless Entry Instrument Panel Electronic Climate Control Infotainment system Central Locking Electric Windows Power Mirrors Directional Indicators Power Tailgate The vehicle would start and operate as expected even with the issue present. A scan tool was connected to the vehicle’s data link connector (DLC) and numerous fault codes were stored. The following codes were found with a full system code scan (see chart on page 21). 26 AFTERMARKET JULY/AUGUST 2021 TECHNICAL/SNAP-ON www.aftermarketonline.net CASE STUDY: VOLVO XC60 MEDIUM SPEED CAN BUS FAILURE A wiring diagram was consulted to investigate the modules which communicate on the Medium Speed data bus. Fig.1 is a simplified diagram showing the modules on the Mid speed network. CEM – Central Electronic Module CCM – Climate Control module ICM – Infotainment Control Module DIM – Driver Information module DDM – Driver Door Module PDM – Passenger Door Module KVM – Keyless Vehicle Module POT – Power Operated Tailgate It can also be seen from the diagram that pin 3 and 11 at the data link connector (DLC) are connected to the medium speed CAN Bus. This is a very convenient point to test the network. A 16-pin break-out box can be used to allow easy access to the DLC pins. Breakout An oscilloscope was connected to the breakout box and the waveform seen in Fig.2 was observed when the faults were present. (Continues on page 28) Damien Coleman is back again with a deep dive into a 2017 Volvo XC60 with multiple electrical issues Fig.1