Checking communication errors, car model S80

HINT: Test the communication with another corresponding vehicle to decide if the malfunction is in the vehicle or in VIDA/VCT/cable harness. If the communication works on another vehicle, the malfunction is in the vehicle.

Different speed on the CAN-communication can lead to problems

Volvo's vehicles have different speed of communication on the high-speed part of the CAN-network (HS-CAN), depending on model year.

Model year -2004 communicates with 250 kbit/s.
Model year 2005- communicates with 500 kbit/s.

Due to this, it is very important to specify correct vehicle profile before any communication is started with the vehicle's HS-CAN. This is normally done by pressing on " Retrieve VIN" or by manually specifying vehicle parameters under "Vehicle profile".

If the wrong model year has been selected, it may lead to blocking of the CAN-net, diagnostic trouble codes being stored in several control modules or missing response from control modules at continued communication. The following control modules may be affected by this problem:

Brake control module (BCM)/(ABS)
Engine control module (ECM)
Electronic Throttle Module (ETM)
Suspension Module (SUM)
Central electronic module (CEM)
Transmission control module (TCM)
Steering wheel angle sensor module (SAS)
Steering Wheel Module (SWM)
Electrical Power Steering Module (EPS)

If this happens, take the following action:

Turn off the ignition and remove the ignition key. Insert the key again in position II.
If the above does not work, remove the battery cable and connect it again after a minute to reset the control modules.
Select the correct vehicle profile in VIDA and erase the diagnostic trouble codes. Check that the symptoms have disappeared.

Diagnostic outlet

Check the voltage feed to diagnostic outlet #16. The voltage shall match battery voltage.
Check the cable for power ground and signal ground to diagnostic outlet #4 and #5.

HINT: When VCT2000 is connected to the diagnostic outlet (is supplied with voltage), the indicator diode shall be activated with a green light. Then the indicator diode flashes quickly when communication takes place with a control module. In case of certain internal malfunctions on VCT2000 the indicator diode is activated with a red light.

Communication cables

Check the communication cable (k-line) between diagnostic outlet #7 and central electronic module (CEM) #D6 and other connected control modules for open circuit, short-circuit to ground and short-circuit to voltage.
CAUTION: In case of malfunction on this communication cable, communication cannot be established on either the low or high-speed network. First when communication takes place on this cable, the low and high-speed cables between the diagnostic outlet and central electronic module (CEM) are connected to the rest of the network in the vehicle. This is controlled via a relay in the central electronic module (CEM). This relay is only found on vehicles of model year -2004.
For communication problems with control units on the high-speed network , check communication cables between diagnostic outlet #6/ #14 and central electronic module (CEM) #B7/#B8 for open circuit, short-circuit to ground and short-circuit to voltage according to references above.
For communication problems with control units on the low-speed network , check communication cables between diagnostic outlet #3/#11 and central electronic module (CEM) #B19/#B20 for open circuit, short-circuit to ground and short-circuit to voltage according to references above.
Also check the communication cables for the low and high-speed net between the central electronic module (CEM) and the other connected control modules according to troubleshooting above.

Control modules

Check that the control module's voltage feed and ground connection are trouble-free.

CAUTION: If none of the above checks help, try reading out diagnostic trouble codes in the central electronic module (CEM). Done via VIDA vehicle communication. A prerequisite for being able to communicate with the control modules in the car is that the central electronic module (CEM) is active and can be communicated with. If communication is not possible with the central electronic module (CEM), check the voltage feed and ground for the central electronic module (CEM).

VCT2000 and cable harness

Connect VCT2000 to the vehicle so that it is supplied with voltage. Test VCT2000 by selecting the system's self-test and VCT Test in the VIDA main menu. If any malfunction is found according to the test, first replace the cable harness then the VCT2000, if the test still indicates a malfunction.
If no malfunctions were found after troubleshooting according to above, try with a new cable harness and/or new VCT2000.

VIDA

If no malfunctions were found after troubleshooting according to above, try performing a complete system reset of VIDA.

Other information

See Contents

Fig 1: Identifying Data Link Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Continue
Refer to Fault-tracing information