Checking The Low Speed Network

The fault source on the bus cable may be a long way from where the check is carried out. Therefore start the check at one end of the cable and work through the bus system methodically until the fault is found. Disconnecting the connector from the control module splits the bus cable into two parts. If the resistance does not correspond to the given value (60 or 120 Ohm) when examining one of the components, the fault is localized in that component.

Information 

• The resistance must be approximately 60 ohms when taking readings on a connected CAN
• The resistance must be approximately 120 ohms when taking readings on a CAN that is not connected.

Check the bus cable. Check for an open-circuit according to OPEN-CIRCUIT, PERMANENT FAULTS . Remember that the CAN bus is only a communication network. There are no fuses, contact breakers or sensors.

HINT: If the fault is detected before all the following cables have been examined, the following cables need not be checked. 

HINT: If possible measure from the rear of the affected connectors so that they are not damaged. 

The following cables and connectors must be examined to localize a open-circuit.

The cable between: 

• driver information module (DIM) #3 and climate control module (CCM) #12A
• driver information module (DIM) #2 and climate control module (CCM) #14A
• Accessory control module (AEM) #4A and rear electronic module (REM) #14A
• Accessory control module (AEM) #3A and rear electronic module (REM) #16A
• rear electronic module (REM) #14A and driver information module (DIM) #8 and intermediate connector 54/40
• rear electronic module (REM) #16A and driver information module (DIM) #9 and intermediate connector 54/40
• central electronic module (CEM) #2D and driver information module (DIM) #9
• central electronic module (CEM) #3D and driver information module (DIM) #8
• power seat module (PSM) #3B and driver information module (DIM) #9
• power seat module (PSM) #2B and driver information module (DIM) #8
• infotainment control module (ICM) #4A and climate control module (CCM) #12A
• infotainment control module (ICM) #6A and climate control module (CCM) #14A
• infotainment control module (ICM) #3A and driver information module (DIM) #3A
• infotainment control module (ICM) #5A and driver information module (DIM) #2A
• carphone module (PHM) #5A and climate control module (CCM) #12A
• carphone module (PHM) #15A and climate control module (CCM) #14A
• passenger door module (PDM) #3A and climate control module (CCM) #12A and intermediate connector 54/11
• passenger door module (PDM) #2A and climate control module (CCM) #14A and intermediate connector 54/11
• climate control module (CCM) #11A and steering wheel module (SWM) #19
• climate control module (CCM) #13A and steering wheel module (SWM) #9
• steering wheel module (SWM) #20 and SRS control module #25B
• steering wheel module (SWM) #10 and SRS control module #23B
• SRS control module #26B and upper electronic module (UEM) #5 and intermediate connector 54/13
• SRS control module #24B and upper electronic module (UEM) #3 and intermediate connector 54/13
• driver door module (DDM) #3A and upper electronic module (UEM) #5 and intermediate connector 54/10
• driver door module (DDM) #2A and upper electronic module (UEM) #3 and intermediate connector 54/10.

Other information 

• To connect the breakout box to the driver information module (DIM), see CONNECTING THE DRIVER INFORMATION MODULE (DIM) TEST BOX
• To connect the breakout box to the climate control module (CCM), see CONNECTING THE BREAKOUT BOX
• To connect the breakout box to the RTI control module, see CONNECTING THE BREAKOUT BOX TO THE ROAD TRAFFIC INFORMATION (RTI) CONTROL MODULE
• To connect the breakout box to the rear electronic module (REM), see CONNECTING THE BREAKOUT BOX TO THE REAR ELECTRONIC MODULE (REM)
• To connect the breakout box to the AEM control module, see CONNECTING THE BREAKOUT BOX. ACCESSORY ELECTRONIC MODULE
• To connect the breakout box to the central electronic module (CEM), see CONNECTING THE BREAKOUT BOX
• To connect the breakout box to the power seat module (PSM), see CONNECTING THE BREAKOUT BOX, POWER SEAT MODULE (PSM)
• To connect the breakout box to the audio control module, see CONNECTING THE BREAKOUT BOX, AUDIO CONTROL MODULE
• To connect the breakout box to the infotainment control module (ICM), see CONNECTING THE BREAKOUT BOX
• To connect the breakout box to the carphone module (PHM), see CONNECTING THE BREAKOUT BOX, CARPHONE MODULE
• To connect the breakout box to the passenger door module (PDM) or driver door module (DDM), see CONNECTING THE BREAKOUT BOX
• To connect the breakout box to the steering wheel module (SWM), see CONNECTING THE BREAKOUT BOX
• To connect the breakout box to the SRS control module:
  • For model year 2003-2004, see CONNECTING THE BREAKOUT BOX .
  • For model year 2005-, see CONNECTING THE BREAKOUT BOX .
• To connect the breakout box to the upper electronic module (UEM), see CONNECTING THE BREAKOUT BOX

Fig 1: Identifying Ohm Meter

Courtesy of VOLVO CARS CORPORATION

Was a fault detected? 

• YES 

  Refer to VERIFICATION 

• NO 

  Refer to REPLACING THE CARPHONE MODULE (PHM)