Ford front ABS Sensors

[MadScience]

One more data point: I unplugged the rear sensor on the diff, and my speedometer still works. That means there's no reason to believe that that sensor is supplying any data either.

It also means that this van is getting the speed data some other way. There's an output speed sensor on the 4r100, I wonder if it just uses that, or it it falls back to it when the ABS data is not available.

This makes me wonder about either the programming or just converting the signal. I'd expect the transmission to be pretty confused if I made it think that it's gearing had changed. Or maybe not, depending on how the tables in it work.

Ordering some F350 sensors for a 99 (well, as soon as I pull the left wheel and rotor to find out which way mine face). Fit looks OK otherwise.

[carringb]

Vans use the transmission pickup for the speedo, and rear axle for ABS.

That rear sensor fault might just be metal on the sensor. Either some shavings from break-in, or sludge from the limited slip clutches. Wiping it off is all it takes sometimes. That said.... most vans of that era have to replace the stock sensor once, but my NAPA one seems to be holding up.

[UJOINT]

Check ALL connections on the ABS wires as well as the rear transmission VSS. On the last van we did they ran speaker wire for the VSS (not even soldered, just twisted up) and did the same on the ABS wires.

[photographix]

Originally Posted by MadScience

...The van is one of the Tijuana conversions. ...

What's a Tijuana conversion?

[MadScience]

Thank you all for your help!! -- Chris, you in particular, please know that neither I, not anyone else expects you to debug someone else's product. I'm writing this down here partially so the information is out there for the next person to run into a similar situation, since I didn't find much in the way of concrete info, other than "swap the sensors" with extensive searching.


Edit: This was bogus, apparently I looked at this too late to properly process left and right images. Mu axle needs one kind of sensor. Interestingly many suppliers list it as "Front Left" when the actual part lists "Front Left Front Right". End Edit. Pulling the other rotor confirmed that my hubs need the mirror image sensors, which makes them less easy to find. However, it would probably be a good idea to confirm that they really are the wrong ones, or bad, first.

Yes, the wires were simply twisted together. I can crimp/solder (I prefer crimping in high vibration situations) the connections to eliminate that possible issue. -- Thinking about it, we're not talking about much of a signal here, so this may be an issue. I did un-do the electrical tape to check for a shorts on both sides. I just re-twisted and taped after I did that, still expecting to just need new sensor. I just didn't want to leave the cable hanging loose.

I pulled the rear sensor and cleaned it, but it reads open (infinite resistance), so it's bad, which was the most likely state anyway. It's marked F85F-9E731-AB, which seems like the right part from the years it's supposed to fit. AKA part # DY1123 which looks like it's up to F85Z-9E731-AB at this point.

Since that was enlightening, I checked the front cables for markings again, and on one of the rubber sleeves I found "C-86421 04" on the drivers side and "C-86421 08" on the passenger side. I was unable to turn up anything on the usual search engines with that.


Driving (city streets, at least 3 miles, over 35, but not over 40), after clearing the codes, only resulted in C1230 "Rear Center Input Circuit Malfunction" coming back. It's unclear that I've managed to get the ABS to fully test, since I'd expect even that to trigger the ABS light, and with that, the C1226 "Brake Warning Lamp" code, which is not back either, and should really come back after the light self-test during startup.

For the moment, I'm ordering just a rear sensor, a DY1123, since that's the only part I'm certain I need so far.


The following seems like a separate issue, or possibly not an issue at all:

I did go looking for a VSS on the transmission output, and there is one, but it's not hooked up. There's also one on the output of the transfer case, which is hooked up to an extended cable that looks like it would have made it to the sensor on the transmission previously. I'm not really sure that that configuration is what I want, if I want the transmission to work correctly in drive in low range (which it does not). Shifting properly honestly seems more important than accurate speed in low range. -- This also tells me that I'll need to use a signal converter if I want to calibrate the speedometer (which is off by tire-size), which is likely the next undertaking.

Completely unrelated: While I was under there, I noticed the bottom bolts holding the output adapter to the transmission were loose. They don't seem to have much to bite into, but that seems somewhat straight forward, so I can hand the van to a shop for that. Sigh. That spot has been seeping a little for as long as I've had the thing, I guess I finally know why.

[MadScience]

Originally Posted by photographix

What's a Tijuana conversion?

Some discussion here: viewtopic.php?f=34&t=10242 (meant to go looking for that post anyway, see my edit). It seems to be a small outfit that converts 1-3 well used vans a month. They represent the bottom end of the market as far as ford van 4x4 conversions go. The sales approach is vague, likening it to other vendors products which isn't really great.

I still don't regret mine, I needed to live with something to learn enough to know better. And honestly, given where I was at the time (recession etc.), I don't think I would have entered the market for much more. Now that my job is a bit more secure again, and I know how much we use a 4x4 camper, I'd be comfortable spending more. However, at the moment I have the van I have, and I enjoy learning about it, so I'm making it work. With hindsight, I'd chose a different route.

[MadScience]

I managed to drive the van a bit more today. The only way I get codes for the front sensors at this point is by unplugging them. So for now, I crimped those wires properly.

A new rear sensor shows up tomorrow. I'll see what that does.

[MadScience]

Popped the new sensor in (literally a 3 minute job), and cleared the code. Now the ABS and brake warning lights cycle and then stay out, and I have no new codes after driving around the block.

I'll have to go someplace less busy to actually try to trigger the ABS. But so far this seems promising.

(Of course, if this does it, I will not have answered my original question, which is which sensors my van uses. That will need to wait until one fails. That said, I suspect it's the 02 4wd F350 parts which differ left and right).

[MadScience]

One more and hopefully final update:

I've learned some things about when fault codes come up: With the rear sensor dead, the front sensors weren't going to throw any code as long as they looked like they were present. The ABS system just thought the van wasn't moving. With the rear sensor in place, it took either ~5 miles or going over 60mph (not sure which, not sure I care) for the fronts to tell me that they didn't see any signal.

Since I was experimenting, I ordered two of these (after checking my pictures and confirming that I was confused and the left and right were identical): http://www.amazon.com/gp/product/B001C6 ... ge_o00_s00 I went with the non-motorcraft since I wasn't sure that it was the right part, and that dropped the cost of experimentation significantly. The equivalent motorcraft seems to be "BRAB68". Whatever you go with, you likely want two of the same, I've come across various stories of miss-matched sensors resulting in problems.

I swapped these sensors in today, and after clearing the codes, went for a longer test drive that included freeway and some loose gravel to play in. The swap appears to have been successful: No codes showed up, and sudden stopping in poor traction results in the expected pulsing and no lock-up of the wheels.

[Viva]

Great perseverance and sleuthing skills! Nice to hear the outcome and I bet someone(s) searching in future are going to be really glad this information was saved.