Service Kit Bulletin
Date: May 1, 2025
Bulletin Name: FDM-SVC-041
Model: Oshkosh S-Series
Units Affected: 2.0 Front Discharge Mixers

VIN 821990 - 827769

2.0 Telematics Control Unit (TCU)
Upgrade - T17 to T27
Purpose:

This bulletin provides instruction for installing a T27 TCU module in place of a T17 TCU module.

Notice:
• This bulletin should be read and understood in its entirety before performing this procedure.
• All procedures outlined in the bulletin must be performed by skilled service personnel. Refer to the product
service manual for descriptions of maintenance procedures.

SAFETY NOTICE

SAFETY NOTICE

Perform your company’s Lockout/Tagout
procedure. If your company does not have a
Lockout/Tagout procedure, follow OSHA
1910.147 and 1910.146 Confined Space as
appropriate.

Use appropriate Personal Protective
Equipment (PPE) as required by your
company.

Tools and Equipment Required
Customer to supply:
• Hand tools
• Drill and 3/16” drill bit
• Tape measure
• Torque wrench (inch pounds)

Parts Required
Item

Part Number

Description

1

A000V858

WASH, FLT, SAE #8 X 0.44 X 0.05 SS

2

2

A000W843

SCR, BTN, SOC #8-32 X 1.12 SS

2

3

A001C246

NUT, ACRN #8-32 SS NS

2

4

A001F369

WIRE HARN, JUMPER, TELEMATICS_SVC

1

5

A001K385

MODULE ASSY, TCU, 12.0.0 X

1

6

A000E542

LOCTITE, #242

1

Qty.

A/R

Procedure:
Lockout/Tagout
1. Place unit on a flat surface, engage parking brake, chock truck tires, and perform your company’s Lockout/
Tagout procedure. If your company does not have a Lockout/Tagout procedure, follow OSHA 1910.147 and
1910.146 Confined Space as appropriate.
2. The vehicle’s BATTERY DISCONNECT switch is located on the left-hand side of the battery box. Use the
battery disconnect switch when performing any maintenance so the vehicle cannot accidentally be started.
a. Turn the battery disconnect switch (Figure A, Item 1) counterclockwise so the hole on the switch aligns
with the hole in the bracket (Figure A, Item 2).
b. Install the safety lockout device ring (Figure B, Item 1) through the holes on the battery disconnect switch
and the bracket.
c. Install a padlock (Figure B, Item 2) onto the safety lockout device ring, lock it, and put the key in your
pocket. If more than one person is working on the vehicle, each person must install his or her own padlock.

1

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Th
be is en
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Un
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1

2
Figure A

Figure B

2

T27 Module Installation
3. Remove four screws and washers securing radio panel to overhead console. See Figure 1. Save screws and
washers for reinstallation of radio panel.
4. Disconnect harness connector and antenna cable from back of radio. Set radio panel aside.
Screws and
Washers

Radio Panel

Figure 1

2

5. Disconnect cab harness connector C1530, GPS antenna connector, and cellular connector from T17 module.
See Figure 2.
6. Remove screws and lock nuts securing T17 module to bottom of overhead console. See Figure 2. Screws
and lock nuts will not be reused.
7. Remove T17 module from overhead console. See Figure 2. T17 module will not be reused.

Cab Harness
Connector C1530

Cellular Connector
GPS Antenna Connector

Mounting Hardware

Figure 2

8. Mark and drill two 3/16 inch holes in bottom of overhead console per dimensions in Figure 3.
2.06

4.118

3.37

2X Ø 0.188

Figure 3

3

9. Place T27 TCU module (A001K385) in overhead console through radio panel opening. See Figure 4.
10.

Apply Loctite® #242 (A000E542) to threads of mounting screws (A000W843).

11.
Secure TCU module to overhead console through holes drilled in Step 8 with screws (A000W843),
washers (A000V858), and acorn nuts (A001C246). See Figure 4. Install screws from top and washers and acorn
nuts from the bottom, acorn nuts to be visible from driver’s seat. Final tighten hardware to 17 in lbs.
12.

Connect GPS antenna and cellular connectors disconnected in Step 5 to TCU module. See Figure 4.

13.

Connect jumper harness (A001F369) to TCU module. See Figure 4.

14.

Connect cab harness connector C1530 disconnected in Step 5 to jumper harness. See Figure 4.
Cab Harness
Connector C1530

Jumper Harness
(A001F369)

Antenna Connector

Cellular Connector

TCU

(A001K385)

Screw (A000W843)
Flat Washer (A000V858)
Acorn Nut (A001C246)
Figure 4

15.

Reconnect harness connector and antenna cable disconnected in Step 4 to back of radio.

16.
Reinstall radio panel to overhead console with four screws and washers removed in Step 3. Final tighten
screws to 75 in lbs.
17.

Remove lockout/tagout and tire chocks.

4

ClearSky™ Verification
18.
Make sure truck is in a location with adequate cellular and GPS service. Truck may need to be outside for
adequate service.
19.

Turn truck ignition switch to ON position and wait until overhead display shows home screen.

20.
Log into ClearSky (https://clearsky.mcneiluscompanies.com) See Figure 5. If an account needs to be
created contact ClearSky support ([email protected]).

Figure 5

21.

Search for truck serial number (last six digits of truck VIN) in ClearSky search window. See Figure 6.

Figure 6

22.
Make sure the truck’s serial number appears in the search results Assets window and select the truck
from the search results. See Figure 7.

Figure 7

23.
Make sure the truck VIN displayed in the information box in the upper left corner of page is correct. See
Figure 8.

Figure 8

5

24.
Check the GPS by clicking on the SUMMARY tab and making sure the map shows the current location of
the truck. The time stamp displayed should be within 2 minutes of the current time. See Figure 9.

Figure 9

25.
Check the ClearSky data by clicking on the TRUCK GAUGES tab and making sure the ClearSky gauges
match what is shown on the gauges in the truck. See Figure 10. Gauges include fuel level, front air tank
pressure, rear air tank pressure, odometer, and engine hours.

Figure 10

6

26.
Click UNIT DATA tab and make sure a report named IGNON appears near top of REPORTS sub-tab with
a DATE/TIME with the vehicle’s ignition turned ON.

Figure 11

27.

Click CONTROLLER INFO tab and make sure information for the following eleven parameters exist.
• VIN
• IMEI
• ICCID
• ENGINE SERIAL/SOFTWARE VERSION
• ABS SOFTWARE VERSION
• DISPLAY SOFTWARE VERSION
• FCM SOFTWARE VERSION
• RCM SOFTWARE VERSION
• TRANSMISSION SOFTWARE VERSION
• INSTRUMENT PANEL SOFTWARE VERSION
• ENGINE REFERENCE TORQUE

Figure 12

7

ClearSky™ Troubleshooting
1. Make sure TCU version number populates in overhead display ABOUT screen. If TCU version is not
populated the TCU is not communicating.
a. Check for a solid red LED and flashing green LED on front of TCU. See Figure 13. No lit LEDs on front of
TCU indicates no power to TCU.
b. Make sure TCU connectors are fully seated and there are no bent or damaged pins.
2. Make sure GPS antenna and cellular cables are connected correctly.
Cellular Connection

LEDs display here
through TCU housing

GPS Antenna Connection
Figure 13

3. Turn vehicle’s battery disconnect switch OFF and wait until LEDs on front of TCU turn off, the TCU has an
internal battery which can take up to 3 hours to fully drain before LEDs go out.
4. Turn vehicle’s battery disconnect switch ON.
5. Turn vehicle ignition switch ON and recheck if TCU is operating and populates the version number in
overhead display ABOUT screen.
6. Contact S-Series service if these troubleshooting steps do not correct TCU operation.

Continuous Improvement:

The change included in this document is part of the
McNeilus Continuous Improvement Process.
McNeilus’s quality policy is providing customer satisfaction
through innovative products, dedicated service, and a
constant focus on continuous improvement.
8

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