For a complete wiring diagram Refer to Section 8W.When Monitored:Continuously with the engine over 600 RPM.Set Condition:When the internal battery within the siren does not charge as expected, the ITM sets this code.Possible CausesVEHICLE STORED WITH NO BATTERY VOLTAGE FOR EXTENDED PERIOD OF TIMESIREN1. DETERMINING IF DTC IS CURRENTWith a scan tool, read and record DTC(s).With the scan tool, clear DTC(s).Start the engine and allow it to idle for 2 minutes then turn the engine off.Using the scan tool, read ITM DTC(s).Does the DTC reset?YesGo To 2NoDTC is not active at this time. Test complete.2. VEHICLE STORED WITH NO BATTERY VOLTAGE FOR EXTENDED PERIOD OF TIMEIf the vehicle was stored with the battery disconnected for an extended period of time the back up battery located in the siren may discharge and need to be recharged.Was the vehicle battery power just restored after the vehicle was stored with no power for an extended period of time?YesAllow the vehicle to sit with a fully charged battery for two hours then restart this procedure.NoReplace the Siren the in accordance with the Service Information. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) .