9400i abs help

Ok, no sweat. There are some things you can do. But chances are you will need to go to a dealer. Tip - If you have an International, don't go to Peterbilt for something like this. International techs will know better where the ABS ECU and the wiring is, trucks are not the same! Chances are you have a Bendix system. I think Wabco has the diagnostic switch, so if you can't find the switch, I would say you have a Bendix. Plus, back then, Wabco was pretty rare as and ABS system on Int'l. Lots of bad things can happen when you have to boost a truck. If the lights stay on solid at key-on I could mean the ABS ECU is not powered. A correctly working ECU will actually turn the light off. At key on, hold down the brake pedal and you will hear the system doing start up checks. Bendix will do a "chuff" test of the all the modulator valves one-by-one and then repeat. If you don't hear this then the ABS modual is not powered. Try checking your fuses/breakers behind the glove box. It should be 30 amps, usually located in F10-A. If is blown or popped, simply replace or reset it. If the fuse is ok, you will need to physically locate the ABS ECU. Back then International kept changing the ECU location to prevent failures from the environment. I could be mounted on top the rear relay valve. It may be mounted to the frame rail some where near the trans on either side. You can manually reset one. You have to have it plugged in with the key on. Bendix ABS ECUs are nice because they actually have fault indicator LED on then to signify the fault. So look for a box about 6"X6" about 1" thick with some LED lit on it, (it may be painted over). The way you reset one is to take a magnet and hold it over the "reset" spot of the housing. There is no button there or anything. The word "reset" is just molded into the plastic. Inside there is a magnetic switch that will reset. Simply hold the magnet to the housing, all the LEDs will lite. Hold it there for about 2 secs and take away. Turn the key off and then back on, see what you get. Sometimes the ECU just gets locked up, some codes are actually internal memory faults where the actual fix is just a good ol' reset. If this doesn't work, then either ignore the ABS light or you will have to bite the bullet and take it in to someone you feel is capable. Good Luck!

 

Ok, lets go one step further... Your system won't have any "mid" sensors or modulators. If you look, you will only see the ABS wheel speed sensor wires going to the rear rear axles. The rear modular valves operate both rear axles at the same time, (just saves money). But Bendix does have the ability to have full 6 sensor/6 modulator. So the ECU is thinking the mid should be there when in fact it isn't, that is why it is reading the fault code. The fix for this is a complete ABS system reconfiguration. What you do is go back under and hold the magnet to the ECU. All the lights will come on. Hold the magnet there, usually after about 30 - 45 sec the ECU is start it's reconfiguration procedure. You will know because the the LEDs will start to flash differently, kinda like the "Knight Rider" car. Once they start to blink like that, take the magnet away and see what happens. You may need to key off and on again.
P.S. You still need to fix the wheel seal though, sorry! Hope this helps!

 

Good to hear. I'm happy to help.

 

Hey Heavyd, you seem to have a lot of knowledge with air brake systems, are you familiar with Freightliner brake systems? I have a 02 Century . The problem with it is when the yellow button is pushed air comes out of the abs valve under the 5th wheel. This valve pressurizes or evacuates the rear of the brake chambers, I am not sure what it does, I am kinda confused about this whole system. Is this the chamber used when on the peddle ?

 

Yah, what you have there is kind of a funny problem. Normally when you push in the yellow button air is supplied to the front half of the spring brake to compress the parking brake spring and release the brakes. The valve under the 5th wheel is called an ABS modulator valve that will control and modulate service brake air to that wheel to prevent wheel lock up when moving. There should never be air leaking from that valve went you just release the park brake. The air that is leaking out the ABS is actually leaking out the exhaust port the way it is supposed to when you release your foot from the brake pedal. The problem is there when you aren't hitting the pedal. What you likely have is a bad maxi chamber. Air is leaking inside the maxi from the spring side to the service brake side, probably through the center push rod seal. The air will leak out the service side and out the exhaust port of the ABS valve. The way to confirm this is to remove the service line from the maxi that the ABS valve modulates. If there is air leaking from the service line when the brakes are released you have found your problem. Just take all proper safety precautions, and have your truck properly blocked so you don't run your self over! I have actually seen one truck that all 4 maxi did this and was completely mind boggled! Then I asked the owner if the truck sat and didn't move for a while, he said yes actually it sat in one spot for two years!

 

This sounds like the same problem I am having. If I pinch the service line to the air chamber the leak at the maxi stops so is this the air chamber on the axle allowing the air to ecsape? This only happens on the passenger side. Any suggestions? Any information is very helpful.

 

Probably a bad maxi. If you are releasing the brakes and the maxi is leaking air out the side or somewhere near the front of it you need a new maxi chamber or piggy back chamber. If it the chamber is leaking with the brake pedal pressed down it might be just the service diaphragm leaking at the base the chamber.