2nd Gen Non-Engine/Transmission ABS and Brake lights on intermittently

[PCrable]

Hi All,

I have a 1998. 5 Dodge Ram with 4WD and 4 wheel ABS. The ABS and brake warning lights have been coming on on the dashboard intermittently now for the past few weeks.



I did a search in the forums and found some other people having this problem. One suggestion was to replace the rear wheel speed sensor. Well... I tried that and it didn't solve the problem. I did see another thread that suggests a possible vacuum leak, but I'm not sure what tools I would need to help track that down.



The truck is also starting to get some noise when you turn the steering wheel pretty far... my guess is the power steering pump is starting to go. I only mention this in case it may somehow be related to the ABS and Brake light issue. The truck's brake lights do work, so it would not appear to be the brake light switch.



The brakes appear to work ok except for some warped rotors.



I went to Autozone and had them check the codes from the computer. Not sure if any of these are related, but here's what they have:



622

463

1693



Anyone have ideas on where I should look next ?



Thanks,

--Phil

 

[AKAMAC]

Do you have cruise control and does it work? There was a re-call on the clock spring for M. Y. 2000/01. Same symptoms.

The codes that are showing are electrical. I would look at possible ground or loom/connection problems at PCM and ECM. Mike

 

[PCrable]

The truck does have cruise control... I'll have to check to see if it works. I'll post results after I can take a test drive.



Thanks,

--Phil

 

[PCrable]

The cruise control works

 

[SteveMiller]

I got the same thing going on. I have a 97 though so minimal electronics and no front abs.



The first time it happened the fuse blew so all I had to do was replace it this time I haven't been able to figure it out yet. My cruise works too but my rear ABS is definately not working. The rear side slides around pretty good when I stop on a wet road.



Any indication that your brakes (ABS) aren't working correctly.



May not be the same problem on mine. I haven't done the wheel speed sensor yet in the rear but I'd like to get this figured out.



If anyone has idea on what to do to track down the problem that would be great.



Steve

 

[AKAMAC]

Phil,

Go ahead and check the ground points on the truck. The codes you are having are all electrical in nature. They are multiple but easy to find. Just loosen the grounding lug nut, spray with an electrical cleaner, re-tighten. If there is corrosion visible you will have to hit them with a wire brush. You can also pull the PCM connections and apply di-electric grease to the plugs. Oh! be sure to pull the neg. batt. cables before doing this. You don't need to possibly exacerbate the problem. You will have to calibrate the tps/apps when done. Mike

 

[GAmes]

I don't know about the 98. 5 but the 97 has two wire bundle connectors behind the front wheel liner on the drivers side. Pull them apart and check for water. One of them has the connector for the trailer brakes in it, and when moisture is inside it has a small amount of current flow to ground that triggers the ABS light.

 

[PCrable]

I'm not thinking that it's just an electrical problem. The truck is starting to have some pretty shaky stops... kinda like very warped rotors.



I'll try looking at the ground and for a harness connection tomorrow and then also pull the tires off to make sure it's not anything like a leaky rear wheel axle seal getting the pads all oil soaked.



Thanks for the suggestions so far.



--Phil

 

[DMC]

If you are getting the brake and abs warning lights check all of your vacuum hoses. If all connections appear to be good. You need to borrow a vaccum gauge and check the low vacuum warning sensor and rule out the possibility, that 1 either it is bad, 2 that you have between 10 and 25 in/hg of vacuum on your system. I bought a mighty vac tester kit at Sears and like it pretty good. There are a lot of ways you can use it.



Have you noticed the brake pedal getting hard to push?



Do you have a factory service manual? If not you need it.



Good Luck



Don

 

[PCrable]

DMC,

thank's for the lead on the source for a vaccum tester at Sears.



The brake pedal doesn't seem any harder than it has been... the only other symptom besides the lights is the apparent rotor warp (if it's related).



I do have the Service Manuals.



I am wondering if the Dealer could help me narrow it down especially the 1693 code and what companion module is reporting a fault. Autozone gave me the main ones, but I guess they couldn't get anything from the other modules.



My guess is that they will charge me $75 just to look at it.



--Phil

 

[FourBarR]

i had a problem with intermittent abs light ,and brake light coming on . i to replaced the sensor,didnt work, found abs harness chafed thru at left rear wheel. check to see if its tie wraped just forward of the rear spring. hope this helps.

 

[PCrable]

Well I finally pulled the tires off to isually inspect the brake systems over the weekend.



I pulled the rear drums and no axle seal leaks. Things were kinda dusty, but nothing obvious to explain the ABS and Brake lights coming on. I checked the wiring and everything going forwar looks fine.



I did adjust the rear star wheel and it seems like the driver's rear drum is slightly out of round since you only hear the pads drag on part of the rotation... . But that's another story...



On the front brakes, I pulled the front tires and just did a visual inspection. I pulled the calipers off and cleaned and lubed the slides and pins while I was there, but nothing obvious. The pads did have some cracks in them, so maybe when I go get the rotors and rums turned, I'll have them check the pads too since they're the Brakes Plus lifetime warranty ones.



Anyhow... still trying to narrow down the ABS and Brake light cause. I would still lean to an issue with the vacuum. Is the power steering pump related in any way to the ABS ?



I'll keep you posted...



In the mean time, it's time to put in another lift pump since my current one is leaking out of the electrical plug



--Phil

 

[DMC]

PCrable:



I don't think your power steering has anything to do with your truck's brakes. The hydro boost came out (I think) in 97 or 98. I recomend you find the vacuum line going into the firewall on the passenger side, from the engine compartment. If you will take a piece of rubber hose and block off the side that leads back towards the vacuum pump, you will be able to determine that the problem is, or is not within the cab.



I discovered on my truck,that the vent/defrost door actuator under the dash was the first item I need to replace for this problem.



By using the vacuum tester I found out that my vacuum pump is in good shape, it produces about 25 in/hg of vacuum at idle.



If you see a fuel leak at the electrical terminals near your lift pump, this is going to be the prefilter/fuel heater assembly. It could be possible that this is your problem not the lift pump. While you have the assembly off get a service kit for the prefilter, and replace the hoses if they have any cracks.



I hope this helps.



You should try and create a description of your truck, in your signature.



All of this info is based on what I know about the 96 year model truck.



Good Luck



Don

 

[PCrable]

Don,

thanks for the help so far.



My signature is included in the first post of this thread. The Bulletin board does not include it by default on subsequent posts on the same thread.



I think I'll post a seperate item for the fuel leak. Not sure if the 98. 5 24 valve has the same configuration as the 96. Maybe I'll get lucky and it will just be a hose that's leaking... hard to see back there to tell.



I think I'll have to look into the vacuum pressure next



Thanks Again,

--Phil

 

[DMC]

Sorry about the omission on your signature. I did scroll all the way up and see it.



Do a search on hydro boost brakes, and you should be able to find out what year they went to this system, I believe your truck has hydro boost.



Let us know of your progress.



Good Luck



Don