Checking The Component And Wiring

The diagnostic trouble code (DTC) indicates that the communication between the left-hand gas discharge lamp module (GDL) and the central electronic module (CEM) is interrupted. This may be due to a fault in the cable between the control modules or a defective communication device in one or both of the control modules.

Check the cable between the central electronic module (CEM) and the left-hand gas discharge lamp module (GDL). Check for an open-circuit. Check for a short-circuit to ground.

Take readings between:

• Central electronic module (CEM) connector terminal #G26 (#26) and left-hand gas discharge lamp module (GDL) terminal #A12.

Also check that the fuse for the headlamp is intact. Replace the fuse if necessary.

Other information 

• see CONNECTING THE BREAKOUT BOX (2004-07)
• see SIGNAL DESCRIPTION CENTRAL ELECTRONIC MODULE (CEM) (2004-07)
• see LOCATION OF COMPONENTS (2004-07)
• see CONTROL MODULE RELAY BOX PASSENGER COMPARTMENT
• see CHECKING WIRING AND TERMINALS

Fig 1: Identifying 8-Bit Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Ohmmeter

Courtesy of VOLVO CARS OF NORTH AMERICA.

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to REPLACING THE CONTROL MODULE