The CVRSS module continually monitors operating conditions for system malfunctions. By comparing system conditions against standard operating limits, certain circuit and component malfunctions can be detected. If a malfunction is detected, a trouble code is then stored in the CVRSS module's memory. These trouble codes can be read later by the service technician as an aid in system repair. Trouble codes can be read through the IPC on-board diagnostic or by using the scan tool. All information in this section will support the reading of trouble codes via the IPC.

NOTE: Operating the vehicle in diagnostic mode for extended time periods without the engine running or without a battery charger will cause the battery to run down and possibly cause false diagnostic information or a no-start condition. To ensure proper operation, use a battery charger if the vehicle is to be operated in diagnostic mode without the engine running for periods longer than ½ hour.

All the trouble codes for the vehicle are displayed (flashed) on the IPC automatically after the diagnostic mode is entered and upon completion of the segment check. Retrieval of only CVRSS DTCs will be discussed in this section.

Each CVRSS trouble code consists of a letter C and a four digit DTC identifier. All DTCs for CVRSS are displayed together, in the order of their four digit number. All DTCs are designated as CURRENT or HISTORY. CURRENT means the fault was still present the last time the diagnostic test was performed, while HISTORY means the fault was not present the last time the test was performed.

If no CVRSS DTCs are present, a NO RSS CODES message will be displayed. If the IPC is unable to establish serial communication with the CVRSS module, due to a problem with either the communication link or the CVRSS power (battery, ignition or ground) inputs, a NO RSS DATA message will be displayed.

The CVRSS module has the ability to store trouble codes as CURRENT or HISTORY. Most CVRSS system malfunctions will cause the SERVICE RIDE CONTROL message to be displayed and set a CVRSS DTC. The fault message will be displayed as long as the DTC is CURRENT. The message will be turned off if a fault is no longer present (i.e., goes HISTORY) during an ignition cycle. HISTORY DTCs are intermittent malfunctions and must be diagnosed differently than CURRENT DTCs. Refer to INTERMITTENTS AND POOR CONNECTIONS in this section for a complete description on how HISTORY DTCs are used to diagnose intermittent faults. If CURRENT DTCs are stored in the CVRSS module, or if the SERVICE RIDE CONTROL message is displayed and no DTCs are set, refer to the CVRSS SYSTEM CHECK chart before attempting any diagnostic procedures.