2nd Gen Non-Engine/Transmission ABS codes - What are these?

[Darrenf]

Hi all,



A while back, I had a shop check the the codes that were showing up as a result of the ABS/brake light being on and here's what came up.



73 – watch dog circuit

65 – Internal MAM Relay Open

43 – RFIxxation Valve Shorted. (There’s a water spot on my receipt and some letters got washed out so that’s what the "xx" is. ) Would the "RF"

point toward Right Front?



I figured the internet would provide me with some info, but no luck.



Do any of these point to an ABS sensor? or something worse?



Here's facts:

-ABS/brake lights intermittely went on and off for a number of months untill finally they're constantly on.

-Rear diff sensor read 1800ohmms so that appears ok.

-No issue with speedometer functionality.



Any ideas?



Thanks!

Darren

 

[Johnny5]

I am curious about this as well since I got ABS codes 65 & 74 some time back and couldn't find any info (see thread below). It was scary since I was highway cruising and the pedal went weak on me but the reset of the codes fixed it... and it has bugged me since because I never found out why.



https://www.turbodieselregistry.com/forums/showthread.php?t=122218



Johnny

 

[jmy]

Hi all,



A while back, I had a shop check the the codes that were showing up as a result of the ABS/brake light being on and here's what came up.



73 – watch dog circuit

65 – Internal MAM Relay Open

43 – RFIxxation Valve Shorted. (There’s a water spot on my receipt and some letters got washed out so that’s what the "xx" is. ) Would the "RF"

point toward Right Front?



I figured the internet would provide me with some info, but no luck.



Do any of these point to an ABS sensor? or something worse?



Here's facts:

-ABS/brake lights intermittely went on and off for a number of months untill finally they're constantly on.

-Rear diff sensor read 1800ohmms so that appears ok.

-No issue with speedometer functionality.



Any ideas?



Thanks!

Darren

----------------------------------------------------------------------

Points to an internal ABS control unit or ABS motor failure.



Your ABS unit should go through a self test each time you turn on the ign. switch. The ABS motor will run to test internal solonoid/valve/functions. The ABS light and brake light will turn on then off.





Does your truck run this test? Does your ABS motor run?



If not check the 40A ABS fuse and the ABS relay in the power control box. Also check connections at the ABS unit (clean with contact cleaner and use dielectric grease) if any doubt.



In most cases I've seen when the ABS motor doesn't run (or runs all time) the problem is due to the failure of the electronic circuit board attached to the ABS module.



Question, were these codes read with a dealer DRB type scanner or from OEM scanner with ABS capability?

 

[Darrenf]

I was afraid you were going to say something like ABS control.



I was looking at it again last night and checked resistance of the front sensors and I got about 1100ohms on both. With each reading the same gives me the impression they're both ok.

I did key on the truck, the lights turn on, then you hear a relay at the control box as the lights go out then come back on. The ABS motor is not running. ABS fuse appears to be good as it looks just like the others in there. I didn't take it out physically and maybe i should have.



It wasn't a dealer that read the codes but an independant shop, not sure what they would've used.



Sounds like i need to start checking prices for the motor and/or control box.



Let me know if you have any other thoughts.



Thanks for the Reply.

Darren

 

[jmy]

I was afraid you were going to say something like ABS control.



I was looking at it again last night and checked resistance of the front sensors and I got about 1100ohms on both. With each reading the same gives me the impression they're both ok.

I did key on the truck, the lights turn on, then you hear a relay at the control box as the lights go out then come back on. The ABS motor is not running. ABS fuse appears to be good as it looks just like the others in there. I didn't take it out physically and maybe i should have.



It wasn't a dealer that read the codes but an independant shop, not sure what they would've used.



Sounds like i need to start checking prices for the motor and/or control box.



Let me know if you have any other thoughts.



Thanks for the Reply.

Darren

___________________________________________________



If the ABS motor won't run i've tested those before by disconnecting the motor plug where it plugs into the ABS controller and jumping +12V and Grd to it momentarly. (the abs motor is in the hyd. control unit just below the ABS electronics controller).





Don't be supprised if the ABS starts to work after you run thr motor by the jumper method. It happens but will fail again after awhile. I've seen em work 2-3 months before failing solid.



The ABS motor was about $700 from dodge last I checked. It's not available from parts houses.

The ABS electronic controller was about $800 dollars last time I checked. It also is not available from parts houses.

I've don't recall the exact price he complete ABS unit whitch includes the motor, ABS electronic control unit and the hyd. control unit.



If you buy a new unit it has to be programmed by the dealer for for your specific configuration (tire size and gear ratio).



I've had good luck with used units from wrecking yards.



The used ABS electronic is about $200.

The complete used ABS unit (motor/ABS electronics/hdy. Control unit) is about $400.



You'll probobly need to go to a yard that can source from any where in the USA to find a match.

They will need the numbers off the top of the ABS unit to do the match. Most yards will give you a parts replacement warranty.



In a case where the motor has previously stopped running I always replace the whole ABS unit with a used unit.



jim

 

[Darrenf]

That's great info! Although disappointing. I'll test that motor and see if I can get it to function for a little while longer. The ABS may have to wait as I'm now in more need of a Torque Converter upgrade. I've got a good source for new and used parts (mostly jeeps and older 4x4's) and he's computerized with a used parts locater so hopefully he can help when the time comes for the whole unit.



Thank you very much for the suggestions and information!

Darren