What Is The Code SPN 1045 FMI 5? (Freightliner Cascadia)

There are basically two types of these codes. The first type is often described as generic. That means they apply to any vehicle and system no matter the brand. The other type of code is brand or manufacturer specific. That means when you see it, that code only refers to a specific brand.

The SPN 2045 FMI 5 is a Bendix-related code and it stands for Stop Lamp Switch Not Detected. The Bendix blink code is 12 and then 1. There may be a problem with one of the stop lamp switches. In this system, there seems to be more than one of those.

To learn more about this code and how to fix it, just continue to read our article. It explores the issue so you have the best information possible. Getting the right information is the first step in any repair especially when it comes to fault codes.

Freightliner SPN 1045 FMI 5


The problem with the official SPN code list, which is the list for Freightliner, Cummins, and Detroit Diesel, is that it was not compiled in a coherent manner.

This list starts with 5-digit codes, then goes to 3-digit ones then to 4, and then back to 3, over to 4 back to 5, and so on. The closest we came to finding this code on the official list was 1041.

But that does not stop us from finding out what the code means or what you need to do to fix it. There should be two stop switches in your braking system that send out signals. They are two-pronged and if one fails on you, you will get this code.

The best option you have when you see this code is to test those switches for continuity and power. If they fail the test you may have to replace the failed switch or switches. Or check your power supply and wires, connections, and so on.

When you test those switches, make sure to disconnect them first. As usual, if you do not like working with electricity, make sure to have a qualified electrician look at the problem for you.

Bendix SPN 1045 FMI 2


This fault code system is a bit different from the SPN FMI code system. It relies on the blink factor and if you are not careful, you may miscount and be led to the wrong fault code.

If you look at the fault code list for Bendix, you will find it under the Misc. DTC code list. The blink code is on the left-hand side and then the description and finally the SID and SPN codes are on the right. The J1587 code is 55 but the J1939 code is 1045 FMI 7.

The code reads- Stop Lamp Switch Not Detected. However, what Bendix does not do with its many explanations and code lists is tell you how to repair the problem.

What they do tell you is- “When using our PC-based Bendix® ACom™ Software, follow the on-screen troubleshooting steps to correct any DTCs. A hand-held tool such as the Bendix Remote Diagnostic Unit (RDU) provides direct access to the DTCs without the need to use blink codes.” (Source)

You have to be careful with the blink code as while the ECU will display the code without a diagnostic tool attached, it will exit the mode if it detects the vehicle is moving.

*** author’s note- we went with the FMI 7 repair because that is the only SPN 1045 on Bendix’s fault code list. However, the repair is the same as the problem is the same. Some dealers may replace the KIT brake switch but there is two of them and you need to repair the right one to clear the code.

The FMI 5 & 2 codes may be on the dealer level lists and can only be read by their scan tools.

Important Information About Fault Codes


As you know the OBD-1 system started in about 1988 when California required all new vehicles sold in its state to be outfitted with OBD-1 technology.

8 years later, in 1996, the oBD-2 fault code technology was implemented and this is the technology still used today. The J1587 usually refers to the initial OBD-1 technology and the J1939 refers to the OBD-2 technology.

There is going to be confusion when you see these different fault codes. The post-1996 vehicles only support a portion of the generic fault codes. Not all of them. The codes supported depend on the year, make, model, engine size, and other factors.

This is one reason you may not be able to see all the codes on any given list. The other problem that confuses a lot of people is that vehicle manufacturers have their own definitions of the same fault codes.

For example, the SAE says for P0740 is a "Torque Converter Clutch Circuit Malfunction", BUT Chrysler will define the same code as "Torque Converter Out of Range".

Then these codes do not always tell you the exact problem that is wrong with your vehicle. They only give you an idea of what is wrong. There have been many cases where an owner has taken their vehicle to the dealer or mechanic and the mechanics, etc., tell them they have no idea what is wrong.

This has happened on the manufacturer’s level as well.

Pulling Codes From The Computer


There are two basic types of code readers you can use. We are not talking about customer and dealer-level scan tools. The first one is the code reader which just about any owner can buy. This tool can only get the codes and no other information.

The second tool is a scanning device. It is a step above the code reader as it cannot only pull codes but get other information from the computers as well. They cost more because they read both the generic and manufacturer’s codes.

Some Additional Words

When it comes to this fault code, it will be best to talk to a Bendix dealer or mechanic. It is a braking system code that does not necessarily appear on all SPN FMI code lists.

Then you have to learn how to read the blink code to get to the right definition. While helpful, these codes are not always easy to read nor are they always easy to find repair information. It takes patience to work with fault codes at times as systems are not always the same.

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