Title:

Command Zone TCU Version 7.4.2 Updates

Number:

SB_736

Release Date:

04/29/2025

Revision Number:

Not Applicable

Revision Date:

Not Applicable

Chassis Type:

All

Component Description:

Telematics Control Unit (TCU)

Subject:
This bulletin provides additional information regarding the Command Zone Telematics Control Unit (TCU), its
functions, device locations in custom chassis apparatus, how ClearSky Intelligence subscribers can request the
latest available TCU software version (7.4.2), and why TCU software should be updated.
NOTE: As this update is a product improvement, it is not a warrantable item.
Purpose:
The TCU is an integral part of the Command Zone multiplexed electrical system installed in Pierce custom
chassis apparatus. Despite its name, the TCU serves many functions in the apparatus – beyond telematics
(ClearSky Intelligence). The TCU supports generation of faults for the Command Zone Display, managing the
apparatus’ WiFi network name/passwords, managing the Administrator login password, supporting the CZ
Webpages application, and serving as a unified data loader for software updates to the TCU itself, the Display,
and the Control Module (CM).
It is important to keep TCU software versions updated to ensure compliance with customer requests for changes
in apparatus systems function, for resolution of discrepancies found in previously installed software, and/or to
provide customers with enhanced system features.
Description:
•

TCU software update to the latest software release (version 7.4.2) is available for apparatus currently
equipped with TCU version 6.0.X or higher.

•

To check current software versions installed in the apparatus’ Display, CM, and TCU, reference Service
Bulletin #732 (‘Validation of Command Zone Software Versions’).

•

Dealers with apparatus currently equipped with TCU version 6.0.X or higher may request TCU version
7.4.2 by submitting a Command Zone Program change request through www.pierceparts.com.

•

TCU version 7.4.2 paired with the CL-714 display enables Over-The-Air Programming (OTAP), provides
minor bug fixes, and feature improvements. OTAP allows apparatus to download software updates to the
aforementioned devices without impact to truck operation. The OTAP payload may consist of any
combination of software updates to the Display, CM, and/or TCU. See Service Bulletin #735 (‘Command
Zone Software Updates – OTAP Method’) for additional details regarding OTAP.

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SERVICE BULLETIN #736

•

TCU software updates may be accomplished via the CZ Webpages application, USB drive inserted into
the Tech Module port, or via Over-The-Air Programming (OTAP). Applicability of each programming
method is dependent upon the apparatus’ configuration. The chart below helps to readily identify the
recommended programming method based upon the apparatus’ configuration:

•

See the following Service Bulletins for details of the respective programming methods:

Method
CZ Webpages
USB
OTAP
•

•

Service Bulletin
SB_733
SB_734
SB_735

Title
Command Zone SPU Software Updates – CZ Webpages Method
Command Zone SPU Software Updates – USB Method
Command Zone SPU Software Updates – OTAP Method

Upgrading from TCU version 6.0.X series software to the new version 7.4.2 software will require a series
of two (2) successive SPU updates:
o

The first update will be performed on the Control Module (approximately 15-20 minutes).
 A file named “SPU,PierceTCU,Job#_Unit#_v7.4.2_v07.25.XX.tar.spu” will be sent via
the technical incident and may only be applied to the Job#/Unit# named in the file.

o

The second update will be performed on the TCU itself (approximately 60 minutes).
 A file, named “SPU,PierceTCU,7.4.2.tar.spu” will be sent via MOVEit, because it is too
large for email. Save this file to your computer because it may be used on every vehicle
that is receiving the v7.4.2 update.

Upgraded from TCU version 7.0.X series software to the new version 7.4.2 software will only require the
single TCU update that will take approximately 60 minutes. The TCU version update is a much larger file
than the Control Module software update.
o A file named “SPU,PierceTCU,7.4.2.tar.spu” will be sent via MOVEit, because it is too large for
email. Save this file to your computer because it may be used on every apparatus that is
receiving the v7.4.2 update.

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SERVICE BULLETIN #736
•

•

When using the CZ Webpages programming method (SB_733), the user will encounter the following:
o

A “Loading…” message will appear on the CZ Display for approximately 10-15 minutes. This is
an indication that the software files are being uploaded to the TCU.

o

The update will then progress to showing a “DECRYPTING” message on the CZ Display. The
message will remain on the display until the update has been completely uploaded and will take
approximately 45 minutes.

o

Next, a “WAITING FOR REQUIRED PACKAGE MANAGERS” message will appear on the CZ
Display and will remain for approximately five (5) minutes.

o

If the upload media/device is disconnected from the truck’s WiFi network, reconnect immediately
once the network shows up. Leave the browser on the CZ Webpages page ‘as-is’ – do not click
on the page or leave the page.

o

If the user encounters a “CONNECTION LOST” message, please disregard and let the update
complete – it is still working in the background. The CZ Webpages page will load back to normal
when the update is completed.

o

Once the update is completed, the user may a see a message on the CZ Display that reads “A
REQUIRED PACKAGE MANAGER OR MODULE IS MISSING”. If this message appears,
please disregard as the TCU software may have been looking for modules not installed in the
apparatus.

When using the USB programming method (SB_734), the total update will take approximately 45 to 60
minutes.
o

As the update is finalizing, a message reading “WAITING FOR REQUIRED PACKAGE
MANAGERS” may appear on the CZ Display. The update is still being completed and this is not
an indication of action required by the user.

o

A message reading “RESULT: ABORT Update aborted” may also appear: if this message
appears, please disregard as the TCU software may have been looking for modules not installed
in the apparatus.

If any additional support is needed, please open a Technical Support request on www.pierceparts.com.

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