Diagnostic trouble code (DTC) information CEM-1A57

Condition 

Fig 1: Locating RTI (Road Traffic Information) Control Module

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble codes (DTCs) are stored if the central electronic module (CEM) registers that communication with the road traffic information module (RTI) is not operating.

HINT: Downloading software from a DVD/CD can cause the communication between the road traffic information module (RTI) and central electronic module (CEM) to disappear while downloading is taking place. The central electronic module (CEM) can interpret this as the road traffic information module (RTI) having stopped functioning and the diagnostic trouble code (DTC) is stored. If downloading has taken place: delete the diagnostic trouble code (DTC), otherwise: fault-trace. 

Substitute Value 

None.

Possible Source 

• No power supply to road traffic information module (RTI)
• Open-circuit in the ground lead to the road traffic information module (RTI)
• Contact resistance in the terminals
• Open-circuit in the wiring for the CAN low speed network to the road traffic information module (RTI)
• The road traffic information module (RTI) is not intended for this car for example a used control module with different software/hardware).

HINT: If several diagnostic trouble codes (DTCs) are stored in the central electronic module (CEM) for communication faults with other control modules in the low speed network, this indicates a common fault in the Control area network, see the wiring diagram. 

Fault symptom[s] 

• Traffic information is not displayed or updated
• The RTI is not working
• The display screen does not deploy.