LEMON Manuals: Even more car manuals for everyone
Home >> Volvo >> 2004 >> S80 Base, 2.5 59, FWD >> Repair and Diagnosis >> Electrical >> Motors, Switches, Relays >> AEM, CEM & Rem Diagnostic Trouble Codes - 7 Of 12 >> CEM-5F4D: Diagnostic System. Too Long (B6284T; 1999-2001) >> Too-long: time >> Checking communication

Checking communication

Check whether the communication is working. Read off the control module P/N in the VIDA communication input for example.

Check if the fault is limited to the Combustion Preheater Module (CPM) or if several nodes have communication problems. If the problem is limited to contact with the auxiliary heater, the fault has been located.

If the communication works and the P/N can be read off, the fault is intermittent.

Remedy as necessary.



Check the cable between Combustion Preheater Module (CPM) #6 and Central Electronic Module (CEM) #18A for a loose connection as described in Loose connections (terminals) and short-circuit to ground, Short-circuit to ground, permanent faults .

HINT: All communication between the additional heater and the central electronic module (CEM) is via this cable. 

Also check the connectors.

Remedy as necessary.

Other information: 

Fig 1: Identifying Connector Terminals
GLL104185Courtesy of VOLVO CARS OF NORTH AMERICA.
Fig 2: Identifying Ohm Meter
GLL101042Courtesy of VOLVO CARS OF NORTH AMERICA.