What Is Freightliner J1587 Code? (Data Link Troubleshooting)
Fault codes seem to be the brainchild of the Society of Automotive Engineers or SAE. This is the group that has designed the fault code system and it is not done in simple, easy-to-understand English.
In pre-2004 vehicles, the J1587 was the conduit for communication between the vehicle data center, the ECM, and the gauges, etc. However, since 2004, it has been restricted to being a conduit between the ECM and the TCM. This allows those two parts to continue to communicate if the J1939 component breaks down
To learn more about this fault code, just continue to read our article. It has the information you want to know about so you can understand what you are to do when you see it appear on your screen. These codes can get confusing and complicated at times.
What Is Error Code J1587?
This will probably depend on the type of vehicle you own. If you have an RV with a Freightliner chassis, then it may be possible to start your engine and use your transmission. But you won’t have any access to the gauges.
On a Volvo truck, your engine may not start and that usually means that there is no power getting to the ECU. You will want to check your wires, connections, and fuses to see if those are the problem.
However, the J1587 fault code has different symptoms when it loses communication contact with other devices. Those symptoms include:
- gauges not working
- ICU displays no J1587, no EnG, or no AbS
- warning lamp(s) such as ABS and CHECK ENGINE on
- cannot retrieve fault codes from an ECU
- ServiceLink® does not connect to the vehicle
- one or more ECUs do not show up on the ServiceLink ECU list
One of the solutions has been to disconnect the battery for 5 minutes to reset the ECM. This is a hard problem to diagnose as mechanics are at a loss for what to do.
Most say to check the fuses to make sure they are clean and no corrosion is on them. That does seem to be the main fix when you see this fault code. That is all one Volvo dealership did to restore power.
J1587 Data Link Troubleshooting
This is a unique fix as it does not require standard mechanical repair work. This code is a communications failure code and no amount of mechanical skill will be needed to fix it.
When it is a communications fault code, then the problem is going to be around every electrical component in your vehicle. This can be time-consuming as you have to check connections, fuses, battery terminals, and so on.
What it turns out to be if the fuses have not blown is that some fuses or wires may have corrosion on them. One dealership had to trace the wires back till they found the faulty connection.
It was corrosion that stopped the truck from operating normally. Corrosion will stop communication between different engine devices. When that happens the code is triggered and you have to search for the problem.
Some owners have been able to drive normally but their gauges do not work Others have had to be towed to the dealership to get the problem solved. There is no one main problem that needs to be fixed when you see this code.
Check your fuses first and there may be at least 5 in one fuse box. Your owner’s manual should be able to tell you where all the fuses and fuse boxes are.
What Is ECU In My Volvo Truck?
This is a computer for your truck. This device has over 100 input and output devices connected to it and it controls the engine, transmission, cooling, and exhaust systems. To name a few of its duties.
When this part is not working, the source of the problem could be just about anywhere. You can solve many of those problems by resetting the ECU. In addition, you may need a diagnostic tool to help read and clear any codes.
The reset should take about 5 minutes to do. There will be times when it is the ECU unit that has gone bad. You may have to take it to your dealer or send it to a company that handles this type of repair.
However, according to at least one mechanic a faulty ECU is very rare. When you see the J1587 code it is usually another electrical component that has failed.
J1587 Communication Error With Vehicle ECU
The first place to check will be your battery terminals and other connections. For some reason automakers made this component series very sensitive and very little can set them off. You want to make sure they are all clean and tight.
Then, if that is okay, you may have to disconnect the power and old elog. This may make a difference but if it doesn’t, then you need to attach your scan tool and see what modules are online and why.
You may have to disconnect and connect each module to do this check. Also, this communication error will trigger the SRS warning light. That light probably will stay on till you find the problem and fix it.
If you do not have a diagnostic tool, then you should head over to your dealer and have them do the work.
Some Final Words
The J1587 code has been given limited duty since 2004. Most often the problem will be a break in communication between the ECM and the TCM. Prior to 2004, you will find that the J1587 had a broader role in engine monitoring.
But it is all about communication between components. Look for electrical problems like corrosion, loose connections, and even blown fuses when you start trying to solve the issue.
Things change over the years as technology changes devices. This information may become old and out of date in a few years.
