Volvo C30 2007 Service And Repair Manual page 316

NOTE: Do not cut the power to the central electronic module (CEM) unless it is the last
control module left to check.
A control module that is communicating incorrectly must be replaced.
NOTE: After fault with control modules that interfere with communication, other control
modules may remain in Limp-Home (that is, they work with reduced
functionality) even when the ignition has been turned off and on a few times.
For certain faults in the CAN-net where control modules have stopped
communicating, it may help to disconnect/reconnect the battery to "restart" the
control module/CAN-net.
Fig. 7: Identifying CCM Schematic
Courtesy of VOLVO CARS CORPORATION
Continue
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Refer to VERIFICATION
VERIFICATION
HINT: Once a fault has been repaired, conduct a verification to check that the fault has been remedied.
Fig. 8: Checking Traffic Load On CAN Cables
Courtesy of VOLVO CARS CORPORATION
2012 Volvo C30 T-5
ELECTRICAL Body Electrical