ABS help

[KeepItSimpleStupid]

The radio might process the speed signal when speed related volume control is enabled. The radio MIGHT be the control interface like it is in some GM cars where various door lock options are enabled. Wipers could also change speed based on speed. The radio and wiper would be right to ignore the input if not present.
So, there's a possible reason for the radio and wipers to get the speed signal.

 

[The Extractor]

Im sure that could be possible. The radio is also not factory so I doubt it interacts with it at all.
This truck is only an xlt which is not top of the line option wise, so if those options were available my truck doesnt have them.

 

[KeepItSimpleStupid]

To me, it just doesn't make sense for all the components to process the SAME raw data, so I just don't think the signal to the instrument cluster, et al is a conditioned (e.g. square wave) of the drive shaft signal.

Family owns a 2000 Impala and it does have the speed compensated volume control. FORD always did things differently, so anything is possible.

==

An off the wall suggestion, but it probably would not work is to use a 4 wheel abs module and simulate the wheel sensor signals from the drive shaft signal. Warning: This is probably not a workable solution.

 

[alec_t]

So should I go for it with that circuit design or do I need more testing to verify the patterns and timing ?

It's apparent from the waveforms you posted that (a) the Vss signal is analog from a variable-reluctance sensor and that (b) the processed output signal is at one tenth the frequency of the Vss signal and has an amplitude of ~10V (which may or may not result in positive and negative peaks, depending on whether it is directly or capacitively coupled to succeeding circuitry). The circuit I posted handles a wide amplitude range for the analogue input and does the necessary frequency division. You could try something based on that circuit, but without C3 and R5 initially (those are the only components significantly dependent on the timing). The 9V regulator would need 'hardening' against transients on the 12V rail, e.g. by use of a TVS diode and RC filter. Decoupling capacitors for the IC supply would be advisable.

 

[The Extractor]

Im going to try the module out of my 01 powerstroke with 4whl abs and see what happens.
Hopefully I dont have a short or bad wiring that kills my other module.


If you look at the wiring diagrams for it the electronic 4x4 and a couple other things go through that abs module.

I dont think the other modules use or need the vss signal but they might for the electronic shift 4x4, ie wont shift above a certain speed etc.

 

[The Extractor]

Scratch that the 01 is totally different.

 

[debe]

I think Alecs circuit in post 28 would be worth a try, probably be better with a square wave to drive the speedo. Forget the ABS module.

 

[The Extractor]

would it be easy/possible to use the old module to build the circuit? or not because it also controls the abs hydraulic unit?

Where would I buy the stuff to build the new circuit? What parts do I need?

 

[bwilliams60]

Just a quick question. What exactly is it that you are trying to do? Does the vehicle not shift properly because of the faulty sensor? Does it not move, erratic braking???? What is it you are trying to fix?
Also, what transmission is in this unit?

 

[The Extractor]

The ABS has 2 parts, the actual hydraulic unit and this module. I removed the hydraulic unit and replaced it with a manual proportioning valve.
The truck worked, (shifted and stopped) great.
Last year I broke the rear axle, twisted the housing on the axle tube, and it seems the abs module broke then as well. Truck doesnt shift so great now.

The truck is a 2000 f350 4x4 automatic, 4R100 trans, electronic shift transfer case, NP273.

The speedo does not work. The trans shifts but not like it should. Trans shifts very poorly in 4x4 Low Range.

I want my speedo back and the trans to shift properly.

 

[bwilliams60]

Okay, couple of things. If you were to replace the ABS sensor, is that the end of your problem or is there more problem. I used to work for FORD and a system with only rear axle sensor escapes me. Is this the Kelsey Hayes EBC2 system? What happened to the module? Usually that is the last thing to look at. Not much problem there. This is a two wire sensor correct? I will check back in the morning. Give me as much info as you can and I will see if I can help you out. Where are you located?

 

[The Extractor]

Hi, thanks for your help.

I dont know which keley hayes system this is.

I have no Idea what caused the module to go bad. It has a code c 1185

2 wire sensor on the rear axle.

Glenwood springs area.



I think my truck is quite uncommon as it has RABS the "ABS" hydraulic unit was attached to only rear brake hardline.,and NO front wheel speed sensors.
There are pics of the control module in the thread but I dont have pics of the hydraulic unit.
I have a code C1185 and I called my local ford dealer and they helpuful and asked a couple questions and said it is probly bad, very rare to go bad but it does happen.
It is an obsolete and superceded part # as well.

If I replaced the ABS Module I am fairly certain it would fix my problems.

 

[alec_t]

would it be easy/possible to use the old module to build the circuit?

Not for building the complete circuit I posted. But if the module is trash, you could perhaps rescue the connectors from it and re-use those.

 

[shortbus=]

Isn't there also the VSS on the adapter between the transmission and transfer case? Doesn't the ABS use the two, tranny and rear sensors for it? What if you just used the transmission VSS output to the ECM? The VSS is the actual speed the truck is moving. The rear axle sensor is the wheel speed and ABS compared the two for the brakes. But pretty sure the tranny VSS just also fed through ABS into the ECM.

 

[The Extractor]

There is a VSS on the trans but it does not go through the abs module. ABS uses only the rear axle sensor. The PCM compares the 2 signals but only uses the axle sensor for the brakes.

 

[The Extractor]

Not for building the complete circuit I posted. But if the module is trash, you could perhaps rescue the connectors from it and re-use those.

Alec what parts do I need to build the circuit and where do I purchase them? Digikey or another suplier?

 

[KeepItSimpleStupid]

You asked about buying parts, but that opens up another can of worms. The two major distributors in the US are www.digikey.com and www.mouser.com
Case, connnectors and prototyping materials are another matter. Surface mount (SMT) is replacing through hole components rapidly. There are sometimes adapters that convert a surface mount device (SMD) to thru-hole. See **broken link removed**. Then there are wire poking non-permanent breadboards. I answered the question generally. Then there is making your own PCB (Printed Circuit Board). Proprietary layout and (Gerbers and drill file) systems exist. Somewhat free (Cadsoft Eagle), free (KiCad) and really expensive stuff exists. Places overseas can do boards reasonably.

 

[shortbus=]

There is a VSS on the trans but it does not go through the abs module. ABS uses only the rear axle sensor. The PCM compares the 2 signals but only uses the axle sensor for the brakes.

Then since ABS is not being used, why not split the VSS signal and use it for the rear axle signal too? The VSS and rear signals are probably being compared in the PCM.

I'd rather work on GM stuff, much less complicated to do the same thing.

 

[The Extractor]

Then since ABS is not being used, why not split the VSS signal and use it for the rear axle signal too? The VSS and rear signals are probably being compared in the PCM.

I'd rather work on GM stuff, much less complicated to do the same thing.

I am pretty certain the PCM has a "list" to compare the 2 signals and I doubt it would work if they were both the same all the time. I thought of combining them as well.

I wouldve rather started with a GM however this truck was a smoking deal.

 

[bwilliams60]

Can you post a picture of the component side of the board and include any part numbers etc found on the outside cover of the unit? I may know somebody that has one of these if it's what I am thinking. If you want, PM me with your VIN # and then I can tell if we are on the same page.

Okay I was just speaking to a local wrecking yard that I deal with and we have the module and hydraulic valve assembly for around $125.00 CDN dollars. I think if you are in the US and you convert, its about $12.oo US..... Just kidding. Anyways, let me know if you are interested.

Less headaches and probably less money in the long run.