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RABS Code 4, need help figuring it out

Bgunner

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Vehicle Year
1994
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Ford/Ranger XLT
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3.0 V6
Transmission
Manual
2WD / 4WD
2WD
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225/70/R15
My credo
If it's not broken Don't Fix It!
I have a 94 Ranger XLT super cab 4x2 with the ABS light on. I pulled the code and I get a code 4 but searching the internet I can not find a list of what the codes mean. As far as I can tell this code means "RABS valve switch closed or open dump valve."

This information was taken from a 91 Explorer and was hoping someone had a book handy to look it up to be sure this is the correct meaning for the code.

I was also wondering, if this is the proper diagnosis, is the valve repairable or will I have to shell out about $130 for the valve assembly to have RABS back?

Some background on the light and truck: I purchased the truck in August of last year and the light was on when I bought it. The person who owned it before ran the truck for about a year and a half with the light on. Before this the truck was stored in climate controlled storage next to classic cars for about 3 years. My understanding is the light was on this whole time. The vehicle was purchased brand new in Virginia and spent most of its life there and only has 145,000 miles on it.
 


Denisefwd93

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stock, may get leveling springs in front "somday"
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I have a 94 Ranger XLT super cab 4x2 with the ABS light on. I pulled the code and I get a code 4 but searching the internet I can not find a list of what the codes mean. As far as I can tell this code means "RABS valve switch closed or open dump valve."

This information was taken from a 91 Explorer and was hoping someone had a book handy to look it up to be sure this is the correct meaning for the code.

I was also wondering, if this is the proper diagnosis, is the valve repairable or will I have to shell out about $130 for the valve assembly to have RABS back?

Some background on the light and truck: I purchased the truck in August of last year and the light was on when I bought it. The person who owned it before ran the truck for about a year and a half with the light on. Before this the truck was stored in climate controlled storage next to classic cars for about 3 years. My understanding is the light was on this whole time. The vehicle was purchased brand new in Virginia and spent most of its life there and only has 145,000 miles on it.
I can't tell what to do, it would have to be your decision. On both my trucks the RABS has been bypassed.
Leave it in and not working with the light on it's not really a solution because It can really cause problems, rear brakes dragging, in my case we went through three sets of rear drums because the RABS, was working like a check valve.
Recent discussion here:
https://r.tapatalk.com/shareLink?url=http://www.therangerstation.com/forums/showthread.php?t=176455&share_tid=176455&share_fid=28487&share_type=t
 
Last edited:

Bgunner

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Location
Western Mass.
Vehicle Year
1994
Make / Model
Ford/Ranger XLT
Engine Type
3.0 V6
Transmission
Manual
2WD / 4WD
2WD
Tire Size
225/70/R15
My credo
If it's not broken Don't Fix It!
Thank you so much for the pic of the codes. To go further into the issue, The rear wheel cylinders on both sides were leaking so I replaces them with new, along with a new break hose on the front and did a full break bleed and get the proper amount of fluid out of the rear, so at least there is no issue with fluid getting past the valves. The rear breaks work well as they will lock up. This is why I want the RABS in it because I live where it snows and the rear likes to come around when they do lock up.

I do not have the red break light on indicating low pressure or fluid. The light does work as it came on at times with the bad wheel cylinders in it and comes on every time I use the E-Break, I have a manual transmission so I use it all the time. I have changed the E-break switch and cleaned the connector at the master cylinder reservoir with electrical connector cleaner and time scraping.

Today, while the kid is in school, I'm going to take the connector off the valves and clean that along with trying to trace the wires to make sure there is no breaks or shorts.

Do you know of a way to test each solenoid valve to tell if they actually activate and move properly? This will help me tell if it is a valve issue or the module in the dash.

UPDATE: I grabbed my trusty multi meter and got 1.8 Ohms on the dump valve and 4.1 Ohms on the Isolation valve. As far as I know the Dump valve is supposed to be 1.2 ohms and the Isolation valve is supposed to be 4 ohms.
 
Last edited:

projectRanger93

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Ranger STX
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Transmission
Manual
2WD / 4WD
4WD
Tire Size
235/75-R15
Thank you so much for the pic of the codes. To go further into the issue, The rear wheel cylinders on both sides were leaking so I replaces them with new, along with a new break hose on the front and did a full break bleed and get the proper amount of fluid out of the rear, so at least there is no issue with fluid getting past the valves. The rear breaks work well as they will lock up. This is why I want the RABS in it because I live where it snows and the rear likes to come around when they do lock up.

I do not have the red break light on indicating low pressure or fluid. The light does work as it came on at times with the bad wheel cylinders in it and comes on every time I use the E-Break, I have a manual transmission so I use it all the time. I have changed the E-break switch and cleaned the connector at the master cylinder reservoir with electrical connector cleaner and time scraping.

Today, while the kid is in school, I'm going to take the connector off the valves and clean that along with trying to trace the wires to make sure there is no breaks or shorts.

Do you know of a way to test each solenoid valve to tell if they actually activate and move properly? This will help me tell if it is a valve issue or the module in the dash.

UPDATE: I grabbed my trusty multi meter and got 1.8 Ohms on the dump valve and 4.1 Ohms on the Isolation valve. As far as I know the Dump valve is supposed to be 1.2 ohms and the Isolation valve is supposed to be 4 ohms.
Did you make any progress on this? I recently replaced my valve and they work, but the ABS light and Brake light are on. I also pulled a code 4, so both lights are related. I did measure my resistances before installing it and they weren't exactly the same as my old unit. So wondering if there's a way to reset the ABS module to accept the new resistances or what else did you do?
 

Bgunner

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Location
Western Mass.
Vehicle Year
1994
Make / Model
Ford/Ranger XLT
Engine Type
3.0 V6
Transmission
Manual
2WD / 4WD
2WD
Tire Size
225/70/R15
My credo
If it's not broken Don't Fix It!
If you are getting both lights then there is more than one issue, most likely. The red "Brake" light means low fluid in master, leak in the system some where OR possibly a bad switch on the master that reads the fluid level. First thing to look at is fluid level on the master cylinder to be sure it is not low. Next is to make sure the wiring at the switch is not corroded and has a good connection, this is located in the master cylinder reservoir. the last thing to check is there a leak in the lines, calipers and wheel cylinders? If all these check out then you may be looking at a bad master cylinder but this can only be determined after testing.

My RABS valves are shot so at this point I am not replacing the unit till the rest of things that are wrong are replaced. There is a computer that controls the RABS in these trucks. I would test this item before replacing more parts to be sure the rest of the system is working properly. This computer is located in the dash usually to the right side of the radio but if not hen located in that area between the radio and the ash try.

Resetting the Rabs valve: there is a rubber covered button on the valve body itself. Some times this will trip and need to be reset It takes some force to reset it once its tripped so a good hard push is necessary. If there is still air in your lines, If I had to guess as to where it would be in the valve body for the RABS, this could cause your BRAKE light on the dash to come on indicating low pressure in the system.
 

projectRanger93

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Ranger STX
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4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Tire Size
235/75-R15
If you are getting both lights then there is more than one issue, most likely. The red "Brake" light means low fluid in master, leak in the system some where OR possibly a bad switch on the master that reads the fluid level. First thing to look at is fluid level on the master cylinder to be sure it is not low. Next is to make sure the wiring at the switch is not corroded and has a good connection, this is located in the master cylinder reservoir. the last thing to check is there a leak in the lines, calipers and wheel cylinders? If all these check out then you may be looking at a bad master cylinder but this can only be determined after testing.

My RABS valves are shot so at this point I am not replacing the unit till the rest of things that are wrong are replaced. There is a computer that controls the RABS in these trucks. I would test this item before replacing more parts to be sure the rest of the system is working properly. This computer is located in the dash usually to the right side of the radio but if not hen located in that area between the radio and the ash try.

Resetting the Rabs valve: there is a rubber covered button on the valve body itself. Some times this will trip and need to be reset It takes some force to reset it once its tripped so a good hard push is necessary. If there is still air in your lines, If I had to guess as to where it would be in the valve body for the RABS, this could cause your BRAKE light on the dash to come on indicating low pressure in the system.
I had recently installed a new master cylinder because my old one was deteriorated. I bled al the brakes when the new valve was installed and it was only after i installed the valve the ABS light went on. The brakes were bled correctly as far as I can tell, plus they feel great. My initial feeling was the pinout being switched on the unit i got. I read the reviews of it on o'reily's webste and people also had problems, said the pinout was switched. I'm going to remeasure the pins and if so, then il have to replace it with a nondefective unit. I will try the reset button you described.
 

projectRanger93

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Joined
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Location
Los Angeles, CA
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1993
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Ranger STX
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
4WD
Tire Size
235/75-R15
So I tried pushing the button yesterday and nothing. It was really hard, i dont think i moved it at all. I tried to trip it electrically by setting the switch pin to ground and nothing either. However, with a help of a buddy i did notice liquid squeezing out of the valve when the brake was pressed, so there is a leak. Didn't have the time to tighten it but i will today and see if that fixes any of the lights.
 

stamina

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Ford Ranger
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Transmission
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4WD
Total Lift
3” suspension
Tire Size
265/75/r16
My credo
built her in a storage unit
If you are getting both lights then there is more than one issue, most likely. The red "Brake" light means low fluid in master, leak in the system some where OR possibly a bad switch on the master that reads the fluid level. First thing to look at is fluid level on the master cylinder to be sure it is not low. Next is to make sure the wiring at the switch is not corroded and has a good connection, this is located in the master cylinder reservoir. the last thing to check is there a leak in the lines, calipers and wheel cylinders? If all these check out then you may be looking at a bad master cylinder but this can only be determined after testing.

My RABS valves are shot so at this point I am not replacing the unit till the rest of things that are wrong are replaced. There is a computer that controls the RABS in these trucks. I would test this item before replacing more parts to be sure the rest of the system is working properly. This computer is located in the dash usually to the right side of the radio but if not hen located in that area between the radio and the ash try.

Resetting the Rabs valve: there is a rubber covered button on the valve body itself. Some times this will trip and need to be reset It takes some force to reset it once its tripped so a good hard push is necessary. If there is still air in your lines, If I had to guess as to where it would be in the valve body for the RABS, this could cause your BRAKE light on the dash to come on indicating low pressure in the system.
can you please shed some more light on this rubber covered button, i just replaced mine because it was leaking and now i have a code 4 but no leaks, please help.
 

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