ABS Light On & Unit Buzzing Code P2509

[Mike Wenrich]

On my 2004.5 I had the ABS light come on and the red brake light after starting it today. Had driven and started several times with no problem so pulled to the curb shut down and started the truck again to see if the ABS message came back. It did so was heading home anyway and when I pulled in at home I heard a loud buzzing sound. Lifted the hood and it was coming from the ABS unit. Would not turn off so I had to disconnect the batteries to stop it. Got a code reader, reconnected and that shows a P2509 which after research does not seem to indicate a brake problem. Anyone have any idea what this problem might be? No brake work done in recent years but what would cause the unit to buzz? It is really loud too.

 

[Mike Wenrich]

Looking further down the recent posts I see one that explains a problem with brakes and collapsing hoses. Could this be a similar problem? The buzzing in the unit was not indicated and my brakes worked okay when driving although I have noticed a slight pull to the right recently so the hoses are definitely suspect.

 

[Ozymandias]

You can not read ABS codes with a generic code reader.
You need Autoenginuity to do so.
Probably you have a broken solder point inside the unit, our MY is prone for this fault.

 

[Mike Wenrich]

Good to know and thanks OZY. Since posting I also found a list of codes I copied from this forum last November and the 2509 is listed as ECM/PCM Power Input Signal Intermittent. That reminded me of the letter I received in 2010 from RAM saying my warranty coverage was extended to lifetime coverage because of faulty programming on Ca. vehicles that can result in a failure of certain state mandated inspection and maintenance tests. Just talks about reprogramming and does not mention this particular problem but.....who knows? This morning a local mechanic suggested I find the fuse/relay sending power to the ABS unit disconnect it and drive knowing you have the older system brakes where you could lock them up. That way it could be driven to someone who could scan for the problem.

 

[Tuesdak]

Buzzing IMO means it's sensing a wheel lockup and wanting to release the brakes. I would have it towed rather than trying to "work around" a brake problem. Not worth the risk to you or your truck. Got AAA or some towing service on your cell phone plan / auto ins? The red brake light being on may be ABS or may be a loss of pressure from a leak somewhere.

One of the most fun ABS issues I have had are where the tone ring breaks and the ABS goes NUTS with 1/2 the signal "missing". NUTS = release the brakes because the ABS thinks they are locking up. One 1999 GM sedan and a 2008 GM van did this to me. I was choosing what to plow into on the 2008 van when "no brakes" from the ABS failure happened. Luckily the parking brake held enough although that stop ruined em.

 

[Ozymandias]

Pulling the fuse(s) is perfectly safe to operate it. Because that's the fail safe mode of the system.

 

[seafish]

Pulling the fuse(s) is perfectly safe to operate it. Because that's the fail safe mode of the system.

IMO that is the SAFEST way to operate the truck ...

the absolute closest that that I have come to a vehicle collision while driving in the last 30 years (please note that I am intentionally leaving out the the first 10 years as a driver LOL) is when I was driving down a gravel road at about 35 mph approaching the middle of a double blind S turn when a UPS truck swung around the middle of the turn taking up well over his half of the road. I would have had time to stop at a wider point in the middle of the turn BUT due to the interaction bewtween the gravel and the ABS sensors, my brakes simply did not work AT ALL in the panic stop situation despoite the brake pedal being to the floor...it took me COMPLETELY by surprise!!! I compensated by going past the ditch and lightly up the embankment allowing both large trucks to pass each other without mishap except perhaps a dirty seat cushion (JK LOL)

Of course,I am NOT advocating removing the fuse simply because of the laibilty involved in doing so, but realizing the limitations of the ABS system is crucial!!!

 

[Mike Wenrich]

Good comments and helpful. Today I found two ABS fuses in the box. The first, No 35, a 10 amp fuse, did not stop the buzzing with power on. The second, a larger 40 amp fuse, No 6 I believe did. But the red ABS and Brake light on the dash is still there. I plan to jack the truck up and check all the pads, front wheels for wobble and likely change the hoses all around. Hoses seem to be available but likely as stated before, not like original. Not sure if I can check for sensor problems or a tone ring but if I replace the parts needed at this point re: routine maintenance then if I take it to a specialist those items are done. I had one bad experience with the ABS as well and leave more distance between me and "clown" cars than ever before. They keep cutting in front of me even when towing not knowing I cannot stop as fast as they can. I guess they have never seen what a Cummin's diesel engine looks like in their lap. This has been a great truck and I've spent very little money on it. I have no problem doing so now to keep it going and the truck reminding me it needs some attention. Any other ideas much appreciated.

 

[MGreer]

Like Ozy stated previously you need a good scanner to read the set dtc. The CAB runs a self diagnostic test on the abs system. When it detects a problem in the system it turns on the lights in the dash and sets a code. The code usually will pinpoint the problem area. Mine did the same thing and set a code for the left front wheel speed sensor. Replaced sensor and all good.
When you pull the fuse for the controller the brakes will perform as normal with the exception of the anti lock feature. I would start with codes before throwing parts at it.

 

[Mike Wenrich]

Good point but some of this needs to be anyway. What code reader would you believe can do the job? I agree I could do all the maintenance and still have a problem like what Ozy mentioned about the solder point. I tend to believe the problem is going to be in the left front as I had a slight pull to the right for a couple months before this happened. But it could be two things wrong so might as well step up to a better reader. Probably need it for something else with the way new vehicles are made and with my 2014 Ram giving me sensor problems. And if I drive it to the local mechanic they charge $165 for a tech line diagnosis after reading the codes. A few of those would buy a reader I imagine.

 

[MGreer]

I have the autoenginuity and it works well.

 

[Mike Wenrich]

Which unit did you buy? I looked on line and it looks like there are units for only RAM and units that are more universal plus it appears you have to buy that and another unit to run it. I'm not a computer guy so I could easily make a mistake here. Would be nice to get something for both trucks.

 

[Ozymandias]

Sadly on our year only the Autoenginuity works really. Cost is around 500$ for the Unit and the Chrysler Software package.
But I don't regret it, it's worth the money.

For example for the ABS, you can show all three wheel sensors as graphs on a single screen. So you see if one is acting up occasionally or permanent.

 

[MichaelOverfield]

I also have AutoEnginuity and found it very effective for my 2009. That said, I somehow came across a wiTech Micropod 2 unit, in every way and form it is the OEM tool, and I found it for less than $150, which did seem too good to be true. I got it because I was looking to re-flash my ECU to see if it would correct a CAN communication issue I've been having. It did work, and with the FCA TechAuthority subscription, you can actually do a flash of any computer that needs one, just like the dealer. It also has all functions and reads codes from all modules and does all actuations and tests, it basically is the OEM tool, now it was a bit strange that it shipped from China, but was "made in the USA", perhaps that is why it was such a good deal! Now the Mopar Techauthority subscription is needed to use the flash function, but the tool can work offline with no subscription and do everything to scan and test all modules on the CAN system. If I can find the site I found it on, I'll post. I think there is also a site called OBD2Tool that has them as well. Consider that option, though the AutoEnginuty will also get it done. Oh, one last note, the wiTech needed a Windows 7 64bit computer, which I happened to already have (can't upgrade it to Windows 10), so if you need a new computer to run that tool, the AutoEnginuty might come in about the same.. but it can't do an ECU reflash, a generic tool that can do that costs about $1200.

 

[Mike Wenrich]

Is wiTech a microsoft computer application only? I have a desktop Apple computer and the wife has an IPad. So I may not be able to run on those but could find an inexpensive laptop for the system if necessary.

Just to eliminate the obvious I pulled all the wheels and checked hoses, pads, etc. Also bled the brakes. Pads are good and no pinched hoses unless they are collapsing from the inside. The wheels are tight so no bearing problem. The ABS lines look okay all the way and no rodent damage detected. Plugged the 40 amp fuse back in and still buzzing. So made an appointment for Wednesday with a local mechanic to read the codes and maybe a tech line call. Driving the truck it feels normal and the slight pull to the right is gone. So whatever it is must be in the ABS system.

 

[sag2]

I also have AutoEnginuity and found it very effective for my 2009. That said, I somehow came across a wiTech Micropod 2 unit, in every way and form it is the OEM tool, and I found it for less than $150, which did seem too good to be true. I got it because I was looking to re-flash my ECU to see if it would correct a CAN communication issue I've been having. It did work, and with the FCA TechAuthority subscription, you can actually do a flash of any computer that needs one, just like the dealer. It also has all functions and reads codes from all modules and does all actuations and tests, it basically is the OEM tool, now it was a bit strange that it shipped from China, but was "made in the USA", perhaps that is why it was such a good deal! Now the Mopar Techauthority subscription is needed to use the flash function, but the tool can work offline with no subscription and do everything to scan and test all modules on the CAN system. If I can find the site I found it on, I'll post. I think there is also a site called OBD2Tool that has them as well. Consider that option, though the AutoEnginuty will also get it done. Oh, one last note, the wiTech needed a Windows 7 64bit computer, which I happened to already have (can't upgrade it to Windows 10), so if you need a new computer to run that tool, the AutoEnginuty might come in about the same.. but it can't do an ECU reflash, a generic tool that can do that costs about $1200.

If it is a genuine Micropod 2 it does not work offline. Only the older Micropod 1 works offline, and only on the older vehicles. Also unless a Micropod is registered with FCA they will not work. It would be interesting to see what you have. Did it come with other software?

 

[MichaelOverfield]

If it is a genuine Micropod 2 it does not work offline. Only the older Micropod 1 works offline, and only on the older vehicles. Also unless a Micropod is registered with FCA they will not work. It would be interesting to see what you have. Did it come with other software?

Well, it has the OEM label, and says it's a MicroPod 2, though the software appears to be what was used for MicroPod 1, but seems to work. It is WiTech ver. 17.04.27. There is a device registration error message that pops up, but you just acknowledge and ignore, and it moves right past it (try to "register" and you get a dead weblink to a defunt website). There is an option to work off-line, as would be needed in trying to do a drive test and data capture, I would find any tool that had no off-line mode to have serious limitations for doing test drive data logging diagnostics. In that mode it appears everything except the flash option is availible. When I had the 7 day TechAuthority subscription, I could log in with the software, and did successfully flash the ECU, actually ended up doing it twice. Seemed to work well, though did not correct the specific issue I'm having, which seems to be hardware, not software.

 

[MichaelOverfield]

Is wiTech a microsoft computer application only? I have a desktop Apple computer and the wife has an IPad. So I may not be able to run on those but could find an inexpensive laptop for the system if necessary.

Just to eliminate the obvious I pulled all the wheels and checked hoses, pads, etc. Also bled the brakes. Pads are good and no pinched hoses unless they are collapsing from the inside. The wheels are tight so no bearing problem. The ABS lines look okay all the way and no rodent damage detected. Plugged the 40 amp fuse back in and still buzzing. So made an appointment for Wednesday with a local mechanic to read the codes and maybe a tech line call. Driving the truck it feels normal and the slight pull to the right is gone. So whatever it is must be in the ABS system.

Yes, you'll find similar for most computer based vehicle diagnostics options.. not sure about AutoEnginuty for Apple products, but in general the market has limited support for Apple, since it's mostly reflected by small and large business that will be using PC based platforms.

That said, a refurbished Windows 7 machine is not going to break the bank and there are some places that will offer an option to include such a machine.

When I started doing work on my more modern vehicles, the first was a VW and I quickly learned that a computer to interface with the vehicle systems was a must. You could not properly do a transmission fluid change, or properly bleed brakes in any car newer than about 2004 without some computer based interface to actuate modes on the vehicle. For the transmission you needed to see the temperature (I also found I could use a non-contact termometer to measure the draining fluid, but a bit cumbersome). That car, and all my newer Cruzes auto transmissions require a fluid level set a operating temeperature, and done while the engine is running and transmission in Park. Best way is to read the temperture from a computer based scan tool, and a standard OBD2 tool is almost certainly not going to have that data.

 

[Ozymandias]

Do you have a link to that wiTech clone?
I'm intrested in it to as I want to have full access.

 

[MichaelOverfield]

This appears to be the same one I got, but I found it at a different site... I'll see if I can find the other site, but this appears to be the same exact thing: https://www.obd2tool.com/goods-5172-wiTech+MicroPod+2+for+Chrysler+Diagnostic+Tool.html