SBW54-083
Service Bulletin Details
Public Details for: SBW54-083
Revised service bulletin for hvac software updates. Description of revisions: this bulletin replaces the version dated 06/21/2022. The model applicability list and the general information have been updated.
Models from 2022
2022 WESTERN STAR 47X |
2022 WESTERN STAR 49X |
Models from 2021
2021 WESTERN STAR 47X |
2021 WESTERN STAR 49X |
Models from 2020
2020 WESTERN STAR 49X |
54-083 HVAC Software Updates 4700 4800 4900 5700 Western Star Service Bulletin 6900 > 47X > 49X > 57X Description of Revisions: This bulletin replaces the version dated 06/21/2022. The model applicability list and the general information have been updated. General Information This service bulletin describes heating, ventilation, and air conditioning (HVAC) controller software updates released on January 4, 2022 that affect the 47X, 49X, and 57X HVAC system. This software update provides resolutions to the following three conditions. • Sleeper vehicles with Battery Powered HVAC System (BPHS) do not turn on the engine fan when using the engine air conditioner compressor. • Sleeper vehicles with optimized idle (O/I) blows hot air when parked. • When running in full A/C mode, economy (ECO) mode automatically turns on after 45 minutes. Only the front control unit (F01T) and rear control unit (R01T) software changes are affected. For reference, the parked control unit (P01T) software update is included in Table 1. These software changes are available for service updates and are backwards compatible. For vehicles experiencing any of the above mentioned symptoms, install the software listed below. If a newer version of the software listed is available, install that. Controller SW Version SW Part Number DiagnosticLink Software Updates Front (F01T) Rear (R01T) 21.28.01 21.28.01 001 448 09 28 ZGS 001 001 448 12 28 ZGS 001 Parked (P01T) 20.35.1 000 448 70 28 ZGS 007 Table 1, DiagnosticLink Software Updates This version of the HVAC controller software contains three changes that affect HVAC operation. See Table 2. Item Affected vehicles: 49X, 57X Sleeper vehicles with BPHS running under very specific conditions do not turn on the engine fan when using the engine A/C compressor. HVAC Operation Changes Symptom Conditions of Occurrence A/C cooling is diminished Specific conditions when the when running in this engine fan does not engage condition. include the following.* • Engine running in parked HVAC and A/C request coming from ACU Resolution FCU and ACU software updates listed in Table 1 correct this issue and allows the engine fan to turn on with an ACU A/C request. • Not in Optimized Idle (O/I) • Parking brake is set • FCU not in A/C request mode (A/C or defrost) Western Star Service Bulletin, 07/13/2023 Page 1 54-083 HVAC Software Updates Western Star Service Bulletin Item Affected vehicles: 49X, 57X Sleeper vehicles with O/I blows hot air when parked. Affected vehicles: 47X, 49X, and 57X LED display located in the FCU A/C button turns from blue to green after 45 minutes of operation. Figure 1 shows the LED in full A/C mode. 4700 4800 4900 5700 6900 > 47X > 49X > 57X HVAC Operation Changes Symptom Conditions of Occurrence When the HVAC is running in Engine is in auto elevate with CPC software version 20.1 or O/I in comfort mode, if programmed for auto elevate earlier and O/I is running in comfort mode. feature and auto elevate activates, the HVAC blows hot air. When selecting full A/C mode Occurs after the center A/C button is pressed. (maximum cooling), the system automatically reverts to ECO mode after 45 minutes, causing cabin temperature to possibly increase. Resolution FCU and ACU software updates described in Table 1 correct this issue and eliminates auto elevate from blowing hot air when running in O/I comfort mode. With the release of the FCU software 21.28.01, parameter A0174479928-002 Manual ECO MODE allows the driver to maintain full A/C mode without the system automatically placing the controller back into ECO mode after 45 minutes. * A/C logic provided by FCU software turns off the A/C clutch if pressure is too high Table 2, HVAC Operation Changes Figure 1 shows the A/C compressor LED illuminated in full A/C mode (blue). When ECO mode is engaged, the LED illuminates green. 04/18/2022 f832249 Fig. 1, AC Compressor LED Display Figure 2 shows the Par_HVAC_Controller_ECO_MODE parameter (A0174479928-002 Manual ECO Mode) used to turn off automatic ECO mode. Page 2 Western Star Service Bulletin, 07/13/2023 HVAC Software Updates 4700 4800 4900 5700 6900 > 47X > 49X > 57X 05/19/2022 54-083 Western Star Service Bulletin f121196 Fig. 2, Par_HVAC_Controller_ECO_MODE Parameter Warranty This is an informational bulletin only. Warranty does not apply. Western Star Service Bulletin, 07/13/2023 Page 3