ABS Sensor/ Stability Control light on!

[Fire488]

Hey guys I would like to run something by you and see if anyone here has any good input on it. I have a 2007 Explorer limited v-8. There are a host of problems I am about to tackle, but the one i hit first is driving me crazy. Now I needed brakes anyway so i purchased everything new and replaced them yesterday. They work very well now and feel like new. The problem is as in my thread title is that whenever it rains or it is humid my ABS light and stability control light comes on. (2 lights) Sometimes when it would not rain for a few days or when it is quite warm out the lights would go out and stay out. Or sometimes the ABS light would be on when i would initially start the truck and two things would happen: The anti locks would engage as i tried to drive for about 10 seconds until the stability control light would come on and then i could drive with no problems. seems to have disabled the systems.
I just purchased a code reader that also does ABS and it did give me trouble codes for the ABS system which were: Left rear wheel speed sensor circuit failure and rear center input circuit failure. I replaced both wheel sensors and the light was out for about a day. Today the lights came back on and I was upset to say the least. I hooked up the code reader and the same codes were stored. Was I supposed to erase the stored codes when i replaced the wheel sensors? Well I did erase the codes and will drive it and see if they come back. I guess I just don't know if I was supposed to erase the stored codes when i replaces the wheel sensors or do the codes erase automatically when the problem is fixed?

Code reader: Cen-Tech OBDII/EOBD+ABS Model: 60974

 

[Fire488]

Aside from the questions in my initial post are there other speed sensors other than the ones on the wheels? Like on the differential or transmission that work in conjunction with the wheel sensors?

 

[Flag Gibby]

Not to my knowledge, the wheel speed sensors provide all the input for the ABS/traction control system. Also, clearing the codes after a repair is not a bad thing because when the codes pop back up then you know that the repair was not successful.
Specifically what codes is it giving you?

 

[Fire488]

Not to my knowledge, the wheel speed sensors provide all the input for the ABS/traction control system. Also, clearing the codes after a repair is not a bad thing because when the codes pop back up then you know that the repair was not successful.
Specifically what codes is it giving you?

Thats the problem. With this code reader (listed above) it did not list a code. It listed the actual part that was failing. I am not sure if I did something wrong with it.

 

[Flag Gibby]

It should give you the specific codes before providing cause/solution tips. You can get the user manual off of harbor freight's website and you can update the software there too if it needs to be updated.

 

[Fire488]

It should give you the specific codes before providing cause/solution tips. You can get the user manual off of harbor freight's website and you can update the software there too if it needs to be updated.

Already updated but I believe you are right. I have to learn how to use the device to get the most out of it. I also for the life of me could not find a speed sensor on the differential. in the area where it should have been there is nothing and there are no wires running to it at all.

 

[Flag Gibby]

That is why I am so confused on the problem descriptions because to my knowledge the older Ford solid axles have one (maybe the new large trucks too but not sure on that), but since we are IRS we don't have one. Maybe the wrong vehicle is selected in the reader?
I would swing by an Autozone and see if they can pull the same codes that you are getting and then go from there.

 

[Fire488]

That is why I am so confused on the problem descriptions because to my knowledge the older Ford solid axles have one (maybe the new large trucks too but not sure on that), but since we are IRS we don't have one. Maybe the wrong vehicle is selected in the reader?
I would swing by an Autozone and see if they can pull the same codes that you are getting and then go from there.

I replaced everything again. All 4 sensors and to no avail. All the rings are good , not cracked , rusty or missing teeth and yet the light still comes and goes. I just don't know what to do. The Ford dealership that i spoke to said that they would just change them all again if they show faulty even though i told him that I did it already. I am completely lost on this and so is the ford dealer apparently.
AutoZone does not check ABS issues.

 

[tripplec]

Have you checked the wiring from that wheel and or faulty or corroded plug the sensor goes into. Odds are there is no signal reaching the computer from the affected wheel. Corrosion is usually the first issue if water got in and then broke or shorted wire from bad terrain crossing. Have you off roaded with it before this started acting up. I sounded like it was ok before you did the brake job. Sensor gap is also import as it sound like its not built into a wheel bearing like many I've seen.

 

[Fire488]

Have you checked the wiring from that wheel and or faulty or corroded plug the sensor goes into. Odds are there is no signal reaching the computer from the affected wheel. Corrosion is usually the first issue if water got in and then broke or shorted wire from bad terrain crossing. Have you off roaded with it before this started acting up. I sounded like it was ok before you did the brake job. Sensor gap is also import as it sound like its not built into a wheel bearing like many I've seen.

This is a street vehicle and the most it has seen is some snow. It is the limited with street tires. I did check all the connectors, cleaned them and even coated the pins with dielectric grease to prevent corrosion and help maintain a good connection for years to come. The connectors were clean anyway. Could be a broken wire too. The problem is apparently with the left rear wheel sensor to which I have replaced three to date, not because they were bad, but because that is where the the code is generation from. The code reader read "left wheel speed sensor" and "center circuit failure" and that is why I originally thought there may be a center speed sensor too. What the hell is the "center circuit"? Anyway, on hot days and when the car is hot too the lights all go out. Cold start up in the morning they are on. I have heard that there is a firmware in the ABS that may need to be flashed as well. I'll keep on keepin on. Thanks.

 

[tripplec]

All I can think is look upstream if you can follow the harness from that wheel. Maybe grounding against the chassis somewhere or scorched by the exhaust if heat affects other systems. A dealers reader would show if a signal was there and if the voltage was within spec. Throwing parts at it (same ones does not make sense especially after the 2nd did nothing) won't fix it. A brake specialty shop might help you fix this issue. Sometimes you have to go to the pros who work on these every day and know where to test for output.

 

[Fire488]

All I can think is look upstream if you can follow the harness from that wheel. Maybe grounding against the chassis somewhere or scorched by the exhaust if heat affects other systems. A dealers reader would show if a signal was there and if the voltage was within spec. Throwing parts at it (same ones does not make sense especially after the 2nd did nothing) won't fix it. A brake specialty shop might help you fix this issue. Sometimes you have to go to the pros who work on these every day and know where to test for output.

Reason I changed them out was because they were replaced for free and suspected damaged. I would not have changed the parts like that otherwise. I did not have a reader at the time capable of reading ABS and now I do. Although it is not as high tech as what Ford would use I just could not justify paying Ford $225.00 just for the diagnosis. All they would do is plug it in.
With all that being said and being out of options I may have to pay for that diagnosis after all. I checked the wires from back to front and there are only to connector points that could be a problem and they are clean. The harness itself is suspended way above the exhaust so it did not melt and I do not go 4 wheeling with this thing so not snags on the harness. I agree about your last statement...

 

[tripplec]

If you had a shop manual it might give you some test points or voltage output that should be seen pulsed as the wheel rotates.

 

[Fire488]

If you had a shop manual it might give you some test points or voltage output that should be seen pulsed as the wheel rotates.

Just got one. Thanks .

 

[Fire488]

I did check the wheel sensors with an ohm meter and they checked out fine. I followed the wiring as far as could. I did not see breaks or damage. Some of the wire loom is not visible but is above the frame so it could not be struck. I removed the connector on the ABS module and the pins and sockets were pristine. I am lost on this one so I am forced to get ripped off and bring it to Ford. The funny thing is that the lights go out on dry warm days or when the engine is hot. The light tends to remain on in the rain all the time. I checked the connectors when it rains to see if water is running on them and they are always dry. One day when the lights went off I used a garden hose on both rear wheel sensors and could not make them come on again. This is nutz.

Anyway here is what my code reader says:
C1175
Left Rear Wheel Speed sensor Input Circuit Failure/
Wheel Speed Sensor Rear Center Input Circuit Failure.

There is no center wheel speed sensor.

 

[tripplec]

Sorry I don't know enough about the specific connection for this that ford has. The ABS computer management interface would be my first point to check and under the hood buss connectors if engine heat plays a role as well.

A brake specialist center would be the best bet and take it when its raining since it needs to be on in the failed state.

 

[Fire488]

Sorry I don't know enough about the specific connection for this that ford has. The ABS computer management interface would be my first point to check and under the hood buss connectors if engine heat plays a role as well.

A brake specialist center would be the best bet and take it when its raining since it needs to be on in the failed state.

Yeah maybe I'll do that instead of Ford being that they are way too expensive. I checked the connections under the hood at the ABS Control Module and they are pristine. AS for the ABS computer I have no idea where to look for that one.

 

[Fire488]

Well funny thing now....I gave the truck to my daughter to run to the store and she told me that the ABS/Stability control lights went out. I just drove the truck to the store and they did not come back on. did the system need time to reset after removing the ABS Module plug? It looked absolutely pristine. Oh well.

 

[Flag Gibby]

The PCM does clear codes on its own once the issue is resolved, but it is not immediate like a handheld DTC reader. In some cases it may take a couple of power cycles for it to happen which is why in some cases pulling the battery connection is helpful on a vehicle to get rid of a check engine light if you don't have a DTC reader.

Oh, good to see that your code reader is giving the actual code now and not just the description... it is much more helpful to have the actual code in my mind.

 

[tripplec]

Signal wires are very low current and millivolt so it does not take much to have them malfunction. Most are gold plated for that reason. Disconnecting and reconnecting could remove some oxide enough to fix the problem.

ABS computer will do a self test with each startup cycle.