Meritor® Rear Axle Temperature Parameters
4700
4800
4900

54-086
Western Star
Service Bulletin

5700
6900
> 49X

General Information
On Western Star 49X vehicles equipped with Meritor drive axles built before April 18, 2022, the high
temperature warning parameter is set too low for some applications. These include vehicles equipped with
synthetic oil and for certain conditions that are not harmful to the axle. If the high-temperature warning appears
and indicates service is required, and the axle is not above the maximum temperature cited in the 49X Driver’s
Manual, the temperature parameters can be changed using DiagnosticLink®.
For vehicles not equipped with synthetic oil, the oil in these vehicle’s axles must be changed to synthetic oil,
which is a non-warranty repair item.

Determining Rear Axle Oil
1. Enter the vehicle’s serial number (S/N) into PartsPro® and search for module 441 in Group 35. See Fig. 1.

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Fig. 1, Module 441 in Group 35 of PartsPro

2. The rear axle oil will be listed in the parts list.
2.1

If the vehicle has synthetic axle oil, go to the procedure below for Changing Rear Axle Temperature
Parameters With DiagnosticLink.

2.2

If the vehicle does not have synthetic axle oil, change the axle oil and the oil in the hub. See Group
35 in the 49X Workshop Manual for instructions. Refer to Meritor service literature for approved
synthetic axle oils.

Changing Rear Axle Temperature Parameters With
DiagnosticLink
1. Park the vehicle on a level surface, shut down the engine, and apply the parking brake. Chock the tires.
2. Connect an RP1210B-compliant vehicle diagnostic adaptor to the laptop and the vehicle diagnostic port.

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Meritor® Rear Axle Temperature Parameters

Western Star
Service Bulletin

4700
4800
4900

5700
6900
> 49X

NOTE: The following steps describe changing the axle temperature values using DiagnosticLink
screen shots with the values expressed in degrees Celsius (°C). If you wish to change units
preferences from Fahrenheit (°F) to Celsius, follow these steps. If not, go to step 4.
3. From the laptop, open DiagnosticLink.
3.1

From the main menu, select ’Tools’ and then ’Options.’ See Fig. 2.

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Fig. 2, Changing DiagnosticLink Units, Step 1

3.2

Page 2

Select the ’Display’ tab. See Fig. 3.

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Fig. 3, Changing DiagnosticLink Units System, Step 2

3.3

In the Display, select ’Units System.’ See Fig. 4.

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Fig. 4, Changing DiagnosticLink Units System, Step 3

3.4

In the dropdown menu, select ’Metric.’ Then select ’OK.’ See Fig. 5 and Fig. 6.

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Fig. 5, Changing DiagnosticLink Units System, Step 4

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Fig. 6, Changing DiagnosticLink Units System, Step 5

4. Ensure that DiagnosticLink is updated to the latest version (8.16 at time of publication). To update
DiagnosticLink, select ’Update’ from the drop-down menu under ’Tools.’ Select ’Program Device.’ See Fig.
7.

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Fig. 7, Updating DiagnosticLink

5. If there are any items in the section ’Request Pending’ downloads, they must be removed. To remove them,
select each ’Request Pending’ list item, then select ’Remove.’ See Fig. 8.

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Fig. 8, Removing Request Pending Downloads in DiagnoticLink

6. Select the ’Gather server data’ tab and select the vehicle identification number (VIN). Then select
’Download data from server.’ See Fig. 9.

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Fig. 9, Downloading Data from the Server

7. A dialog appears with a progress animation as the software is updated. See Fig. 10.

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Fig. 10, Server Gathering Information Screen 1

8. When the data download is complete, a green check mark appears next to the VIN on the ’Gather server
data’ screen. See Fig. 11.

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Fig. 11, Server Downloading Data

9. Select ’Parameters,’ as shown in Fig. 12, item 1.
Once all controllers are connected, as shown in Fig. 12, item 2, select the ’All Parameters’ tab, shown in
Fig. 12, item 3, to read the vehicle parameters.
A green progress bar appears at the bottom of the screen. See Fig. 12, item 4.

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3

1

2
4

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1. Parameters Screen
2. Controller Connections

3. All Parameters Tab
4. Progress Bar
Fig. 12, Server Reading Parameters

10. Select ’Program Device.’ See Fig. 13, item 1. There should be data to upload. Select ’Connect to Server’ to
upload vehicle parameters to the server. See Fig. 13, item 2.

1
2

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1. Program Device Screen
2. Connect to Server Button
Fig. 13, Connecting to Server Screen

11. Remove any items in the ’Request Pending’ section by selecting each ’Request Pending’ list item and then
selecting ’Remove.’ See Fig. 14.

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1. Pending Request Item
Fig. 14, Removing Old Pending Requests

12. Ensure the correct VIN and hardware is populated, then select ’OK.’ See Fig. 15.

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Fig. 15, VIN and Hardware Number Verification

13. A ’Request Pending’ status for the VIN appears in the ’Unit Data’ window. Select ’Connect to Server’ to
download the updated unit data. See Fig. 16.

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Fig. 16, Connecting to the Server to Download Data

14. In the list of parameters, locate ’PACS_Oil_PreWarn_Temp.’ Expand the dropdown menu in the ’Value’
column. Select the value, ’0164430958-001 PACS_OIL_PREWARN_TEMP = 121’ as shown in Fig. 17.
NOTE: The values in this menu are stated in °C; this selection corresponds to 250°F.

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Fig. 17, Parameters Screen Pt. 1

15. In the list of parameters, locate ’PACS_Oil_PreWarn_Temp.’ Expand the dropdown menu in the ’Value’
column. Select the value, ’A0164431158-001 PACS_OIL_WARN_TEMP = 135’ as shown in Fig. 18.
NOTE: The values in this menu are stated in °C; this selection corresponds to 275°F.

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Fig. 18, Parameters Screen Pt. 2

16. In the list of Parameters, locate ’PACS_Max_Time_to_Warn_State.’ Expand the dropdown menu in the
Value column. Select the value, ’A0284570758-001 PACS_MAX_TIME_TO_WARN_STATE = 60’ as shown
in Fig. 19.

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Fig. 19, Changing the Max Time to Warn Parameter

17. Select ’SEND’ and then select ’OK’ to confirm the changes.
18. Select ’Program Device.’ See Fig. 13, item 1. There should be data to upload. A ’Data to Upload’ item
appears in the ’Unit Data’ window. Select ’Connect to Server’ to upload vehicle parameters to the server.
See Fig. 13, item 2.

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Western Star Service Bulletin, 07/29/2022

Meritor® Rear Axle Temperature Parameters
4700
4800
4900

54-086
Western Star
Service Bulletin

5700
6900
> 49X

Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.
Normal warranty applies. See Table 1 for OWL VMRS codes and labor allowance information. Enter this service
bulletin number in the Service Bulletin # field.

Primary Failed
Part
A66-10744-002

OWL VMRS Codes and Labor Allowance
Correction
Component
SRT Code
Description
Cause Code
Code
Code
PARAMETER, AXLE TEMP
003-006-008
93
23
32A-5004B
CHANGE SSAM, (SB54-086)

Time: Hours
0.3

Table 1, OWL VMRS Codes and Labor Allowance

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