What Is Fault Code SPN 5681 FMI 9? (Freightliner)

Finding fault code definitions is not always an easy task as different modules or components are made by different companies. For example, the ABS braking system can be built by Bendix or by Wabco OnGuard. The latter has this code, not the former manufacturer.

To get the definition of the code SPN 5681 you have to go to the Wabco On Guard maintenance manual. It is located on page 18 per the manual and it reads- J1939 Advanced Emergency Braking System 2 (AEBS2) message from the display (or instrument cluster) not received or intermittent.

To learn more about this fault code and what is wrong with your brakes, just continue to read our article. It explores the issue so you have the best repair information possible. Take a few minutes to see how this information can help you solve your fault code issue.

What is SPN 5681 FMI 9


As we mentioned numerous times in different articles, the SPN FMI lists cover a lot of territory. The real problem comes in when some codes are manufacturer specific.

What that means is that while there is an official SPN fault code list, the numbers on it may not apply to all manufacturers. This is one of those cases. The Official SPN list jumps from 55 code to 563, and 569 and then immediately jumps to the 57 code numbers.

It may take some digging but the 56 SPN code numbers may be brake related only and that means you have to know who made your ABS brake system. In this case, it is Wabco On Guard and they have a manual at this link that carries many of their fault codes.

This code is explained as- J1939 Advanced Emergency Braking System 2 (AEBS2) message from the display (or instrument cluster) not received or intermittent. The action you need to take for the repair is as follows: Intermittent power or J1939 network connection to display or instrument cluster.

Verify harness is correct.

Verify correct software version in display or instrument cluster” (see link above).

Important Information About Wabco Systems


As you already know, if there is a problem, then the fault codes will appear on your screen. With Wabco, there are some special pieces of information you should be aware of

1. Only current active fault codes are displayed

2. You can only see the codes with the TOOLBOX software

3. When you have active fault codes, the system may partially or fully be disabled. What takes place depends on if the fault codes are associated with the ACC or the CMS functions.

4. You must clear any other fault codes from other vehicle modules before repairing this code.

5. To clear the CMS codes you must do the following procedure-

After completion of service on the other vehicle system components, cycle the ignition OFF for at least two minutes and then turn the ignition back ON. Start the engine and run it at idle speed for at least two minutes.”

The rest of the information you can get at the link above.

Bendix, The Other ABS System


We are bringing this company up for an important reason. While they do share in the SPN FMI fault code system, they have created their own fault code method.

This system may be hard to understand as it uses blinking lights to tell you what is wrong and the source’s location. Then they have a special method to get to the blink codes

Number of times to press the blink code switch System mode entered
1 Active diagnostic trouble code retrieval
2 Inactive diagnostic trouble code retrieval
3 Clear active diagnostic trouble codes
4 System configuration check
5 Dynamometer Test Mode
7 Reconfi gure ECU (See SD sheet for details.)

In looking at their fault code list, Bendix does not have an equivalent SPN number for this code. But that does not mean their ABS brake system does not experience the same problem.

To clear these codes you need to follow their instructions:

To clear active diagnostic trouble codes (as problems are fixed), simply clear (or “self-heal”) by removing and re-applying ignition power. The only exception is for wheel speed sensor trouble codes, which clear when power is removed, re-applied, and the ECU detects valid wheel speed from all wheel speed sensors.

Alternately, codes may be cleared by pressing the diagnostic blink code switch 3 times (to enter the Clear Active Diagnostic Trouble Code Mode) or by using a hand-held or PC-based diagnostic tool. Hand-held or PC-based diagnostic tools are able to clear wheel speed sensor trouble codes without the vehicle being driven

Clearing Active Diagnostic Trouble Codes

The ECU will clear active trouble codes when the diagnostic blink code switch is depressed and released three times.”

To get all of this information as well as a list of all their fault codes, just click this link. There is also a very colorful diagram of their ABS system which should come in handy for those vehicle owners who have the Bendix ABS system.

Underneath the diagram is important information on how the company’s blink code works. It gives a very accurate description of the speed of the blink code.

According to the Wabco On Guard manual, that company only uses the SPN numbers assigned to it. We did make a brief comparison of the two code lists and it seems the two companies do not overlap in the SPN codes.

Some Final Words

Not all fault codes will appear on the official SPN fault code list. The reason for that is that those codes may not apply to Cummins, Detroit Diesel, or Freight liner components or modules.

You will need to get a Wabco manual or copy the Bendix lists we have mentioned to get the code explanations when they pop up on your screen. Print them out and put them in a file so you have them handy if you are not near a computer.

Old-fashioned storage methods are still valid and very useful.

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