NHTSA ID Number: 11027312
Manufacturer Communication Number: IK2600279
TSB/Document Date: 2026-01-07
Summary
This document provides: Steps to take when switch pack programming fails, or when switch pack disappears after body control module update Sample scenarios Additional information to assist readers in understanding DLB switch pack programming
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TSB/Document ID: IK2600279
Replacement Service Bulletin Number:
MFR Communication Date: 2025-12-19
MFR Internal Campaign ID/Software Version: IK2600279
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ELECTRICAL SYSTEM
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Revision: 4
PROGRAMMING SUPPORT
Created:
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Last
12/19/2025
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4/10/2025
Matthew
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Title : Switch Pack Programming Troubleshooting Information
Applies To : Horizon Vehicles
CHANGE LOG
Please refer to the change log text box below for recent changes to this article:
12/18/2025 - Added key words based on article feedback
06/24/2025 - Added link for the Vehicle Programming Resource Center
04/29/2025 - Initial Article Release
DESCRIPTION
This document provides:
Steps to take when switch pack programming fails, or when switch pack disappears after body control module update
Sample scenarios
Additional information to assist readers in understanding DLB switch pack programming
Switch Pack Programming Troubleshooting Steps
1. First follow the standard switch pack programming instructions found in IK0800590. If problems are encountered, proceed
to the following troubleshooting steps. All steps outlined below are available to dealer technicians. No special access is
needed from tech support.
2. Disconnect door pod #1 (driver's door pod), then attempt switch pack programming again. If this doesn't fix issues
experienced during switch pack programming, move on to step 3.
3. Remove all switch packs from the vehicle. (Make sure you know the serial number of each switch pack.)
4. Install the suspect switch pack in the first switch pack position in your vehicle (be sure to connect both the input and
output harnesses), then program that switch pack.
"Get Data" option can be used to ensure the module data you are seeing is accurate.
5. Once programming is successful and DLB asks you if all switch packs are working correctly, select "No". Selecting "No" is
the only way to get to the next screen that allows you to change the switch pack's source address.
6. The next screen allows you to set the switch pack source addresses. The dropdown menu displays the serial number for
all connected switch packs. Make sure you select the correct serial number on the correct line, then click the "Program"
button.
7. Using the next switch pack that needs programmed, repeat steps 2-5.
8. Once all switch packs that need programmed have been programmed, install them all in the correct locations in the center
panel as shown in DLB.
Return to top
Scenarios
1. One or more of my switch packs does not show in DLB.
A switch pack has been replaced. Some switch packs show in DLB and others do not. (Possible causes: switch
packs having different kernels, or they have duplicate source addresses.)
1. Kernel mismatch - Example: Your truck has 4 switch packs. You are replacing switch pack #3. The replacement
switch pack you get from Parts already has kernel 26 in it - but the rest of the switch packs in the truck have
kernel 24. When you install the new switch pack, DLB does not detect it.
The fix is to program the old switch packs. This will update their kernels from 24 to 25. To accomplish
this, follow Switch Pack Programming Troubleshooting Steps listed above. Once the kernels in the
remaining switch packs are updated to 25, then install the new switch pack with kernel 26. Kernels 25
and 26 can coexist on the same vehicle without any issues.
2. Duplicate Source Addresses - Example: your truck has 3 switch packs. They should each have their own
unique source address (151, 152, & 153). If you are replacing the 2nd switch pack (source address 152) and
you get a replacement switch pack from Parts that is already set to source address 151, when you install it you
would have switch packs with source addresses 151, 151, & 153. Your body controller (and DLB) are not going
to know what to do with 2 different modules broadcasting source address (151). So, in the DLB list of modules
you would only see switch pack 1 and switch pack 3 - switch pack 2 would be missing.
The fix is to program the new switch to the correct source address (for this example, source address
152). To accomplish this, follow Switch Pack Programming Troubleshooting Steps (specifically steps 5 &
6) listed above.
2. Switch pack out of calibration fault (screenshot below) or switch pack mismatch fault.
These faults are not typically caused by the kernels or source addresses. Instead, these faults are typically caused by
switches being installed in different locations in the truck compared to what is shown in the DLB "Center Panel" tab.
Switches and switch locations must match exactly between the vehicle and DLB. Examples of common issues are listed
below.
Example: DLB shows no switch installed in a specific location, but the truck has an unlabeled switch installed. An
unlabeled switch can look similar to a blank cover plate.
Fix: Make sure switches match exactly between DLB and vehicle. Remove switches from vehicle or
move/change switch programming in DLB.
Example: All switches and switch locations match visually between DLB and the vehicle, but the switch packs have
the wrong source addresses. If the switch pack programmed to source address 151 has different switches in it than
what DLB shows, that will cause one of the faults from the screenshot above. This could happen with any of the
switch pack source addresses (151, 152, 153, 154).
Fix: Make sure switches match exactly between DLB and vehicle. Remove switches from vehicle or
move/change switch programming in DLB.
Return to top
Continuing Education
1. Switch packs contain two separate types of programming: a kernel and a source address.
a. Kernel
When you hear the word "kernel", think "operating system". The kernel is the software that runs the switch
pack's functionality.
Only Horizon vehicles (LT, MV, HV, RH…) have programmable switch packs (switch packs that have their own
operating system that can be updated with DLB).
Pre-Horizon vehicles (Durastar, Prostar, Lonestar...) have switch packs, but they cannot be updated or
programmed with DLB (because they do not have a kernel). Attempting to use DLB to program switch packs
on a pre-Horizon vehicle will result in this error:
Examples of early Horizon switch pack kernels are 14, 15, or 16
Examples of current (05/03/22) switch pack kernels are 25 and 26.
The option to update the switch pack's kernel can be found here: DLB > Tools > Switch Pack Programming
b. Source Address
The programming functionality to update switch pack source addresses can be found in DLB > Tools > Switch
Pack Programming.
The source address is the module's unique identifier (name) on the data link. Each module on a vehicle has a
unique source address that it includes in the data packets it sends out on the data link - that way other
modules will know which module the data packet came from.
The source addresses available for switch packs are: 151, 152, 153, & 154
Switch packs with a newer kernel (24, 25, or 26 as of 1/1/25) have static source addresses - meaning each
switch pack keeps the source address programmed into it (even if it disconnects/reconnects to the data link),
unless DLB is used to manually and intentionally change the source address.
Switch packs with older kernels (23 and earlier) have dynamic source addresses. The first switch pack to
connect to the data link would claim the first source address (151). The second one to connect to the data link
would claim the 2nd source address (152). If a switch pack lost connectivity on the data link, it would also lose
its source address. When it reconnected to the data link it would then claim a new source address (the new
source address number would depend on how many other switch packs were already connected to the data
link). Example: if a truck has 3 switch packs (source addresses 151, 152, & 153), and 151 (switch pack 1) and
153 (switch pack 3) lost connectivity, then the switch pack that used to have source address 153 was the first
switch pack to reconnect to the data link, it would then claim source address 151. Then, when the switch pack
that used to have source address 151 reconnected to the data link it would claim source address 153, since
that is the next available source address. If this happened, then when the driver activated the first switch in
switch pack 1, the body controller would send the output signal for the first switch in switch pack 3. Essentially,
the switch signals would get mixed up in the programming resulting in unexpected functions being activated.
The last step of DLB switch pack programming is to set the source address for each switch pack serial
number. So, you need to know which switch pack serial number is in which location in your truck - in order to
be confident that all your switch packs are programmed correctly.
2. All switch packs installed on a vehicle must have the same kernel number. If one of them has kernel 17, the all must
have 17. If one of them has 24, all must have 24. Having switch packs with different kernels on the same data link will
typically cause DLB to see some switch packs, but not others. The only exception is that switch packs with kernels 25 and
26 can coexist on the same truck.
3. New switch packs from Parts (as of 05/03/22) come with kernel 26 pre-installed. It is not possible to get a new switch
pack with kernel 25 pre-installed.
4. DLB will not update any switch pack from kernel 25 to 26.
5. If you obtain a replacement switch pack that has kernel 26, it cannot be revert back to kernel 25. However, kernels 25
and 26 can coexist on the same vehicle and will not cause any issues.
6. The switches and switch packs shown in the DLB "Center Panel" tab must match exactly with the switches and switch
packs installed in the vehicle. Any differences will cause issues/faults - as is covered in Scenarios Step 2
7. Swich packs share their data link with door pods and the lighting control module. It is possible for door pods to cause
issues with switch pack programming. That is why troubleshooting step 2 exists.
Return to top
OTHER RESOURCES
Master Service Information Site
RC2600001 - Vehicle Programming Resource Center
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