ABS light (not VSS, darnit) - Diesel Forum

boatpuller · 08-31-2005, 06:44 PM

My intermitant ABS/speedometer/service engine light/OD light problem is getting pretty much all the time now. I've tested everything I can think of, and am about to spend $500+ for an ABS computer. But first, a question for ya'll:

The ABS light on the dash blinks off roughly every 4 seconds, and then right back on. So it's on for 4 seconds, then blinks off and right back on. Along with the blink, the speedometer cuts out and then right back to the speed I'm traveling. So, every 4 seconds the needle dives for 0 and then right back.

The ABS light even does the 4 second blink off before the truck starts. So, with the key in and turned on, but before starting, the ABS light is blinking off and then back on every 4 seconds.

Can you think of anything else besides the ASB computer? I HATE to spend $500 for something that may not work. thanks.

BTW, I've replace 3 VSS with no change, and tested the wires running from the VSS to the ABS computer for continuaty (sp?) and they tested good. Oh, and I've hit the ABS computer with a hammer handle too. That felt good.

boatpuller · 09-02-2005, 08:49 AM

One more time to the top before telling the boss I bought her a "new computer" as her anniversary gift. [img]/ubbthreads/images/graemlins/shocked.gif[/img]

CSIPSD · 09-02-2005, 11:19 AM

Maybe a visit to the dealer [img]/ubbthreads/images/graemlins/shrug.gif[/img]? As much as I hate giving them $$$ some things you just cant figure on your own [img]/ubbthreads/images/graemlins/phoney.gif[/img]!

boatpuller · 09-02-2005, 12:27 PM

That's a good idea, and one I did when the problem started. They could not get their diagnostic computer to communicate with my ABS computer, and said it was a $900 repair to replace my ABS unit. Sometimes my dealer is sharp, and sometimes they replace an expensive assembly instead of repairing just the broken item. Problem is, I don't know which is the case here.

Following that, I took it to an independent shop who looked at it, and returned it working. BUT, they claim they didn't fix anything, and don't know why it worked after they returned it. It stayed that way for several months.

It's now broken again, but twice in the past 3 weeks it worked perfectly, and sometimes it doesn't work at all. I lack confidence that it really is the expensive computer, but don't know what else to inspect.

Anyway, you had a good idea, and thank you for it.

CSIPSD · 09-02-2005, 12:30 PM

I wounder if something in the diff might be messed up [img]/ubbthreads/images/graemlins/shrug.gif[/img]? I hate little gremlins like that [img]/ubbthreads/images/graemlins/mad.gif[/img]!!

weraracer · 09-03-2005, 01:06 AM

i have a intermitten light as well, but my speedo works fine. sometimes the light will light up while driving then shut off later or not come on at all, or stay on after a few starts.

boatpuller · 09-06-2005, 01:31 PM

That's the way mine started about a year ago. Not saying yours will become like mine....

Just ordered a new ABS computer this morning. Should be in and have an answer later this week. Spending money for improvements is fun. Spending money for repairs bites.

boatpuller · 09-07-2005, 10:04 PM

Update:

Still waiting for the new ABS controller, but decided to hook up a new battery instead of the older one I removed to access the ABS unit (might have worked; stranger things have happened). With the key on, but not started, the ABS light started doing it's blink off every 4 seconds act, but I noticed a clicking associated with it. Tracked it down to the ABS controler under the hood actually making the clicking. Is there a relay or a solinoid or a flasher in the ABS controller?