Intermittent Service Brake Or 4wd Warnings

[mswovela]

Hi all,

 

Sorry for yet another brake problem post, but I'm kinda lost. I've been searching all over for this problem and find the same warning light descriptions but not necessarily the same behavior. Hopefully someone can point me in right direction.

 

'03 Z71 4x4, bought a few months back with right around 100k miles. Maybe once a month a Service Brakes warning, with ABS and Parking warning lamps would come on. Now everywhere I had read pointed to front hubs, but mine also would not have speedometer working when warnings were on and wouldn't shift. Until this week it was very intermittent and when it happened would maybe last for 30-60 seconds and go away. For past few days it was still random, but when it happens it won't quit until I turn truck off and leave it for awhile.

 

Since it wasn't getting any speedometer functions when it was happening, I decided to replace VSS on passenger side of transfer case instead of messing with front hubs. That now at least seems to get me speedometer functions during maybe 1/2 of the times the warning is on now (which is about every time I drive it now). So yea, so progress, but still not sucess.

 

I took it to dealer this afternoon when not only was Service Brakes warning on but the Service 4WD warning was alternating back and forth. Their 'expert' wasn't in today, but they at least pulled codes to say there was no signal from rear ABS sensors. Tech told me that the sensor on driver side of xfer case had been replaced (around 30k miles per svc history), but the wiring was also replaced and spliced in place too.

 

So, long story, still having problems, but hoping to maybe find where to look at this sensor on pass side and especially previously "repaired" connector harness. Any diagrams or thoughts on where to start? Am I even going in the right direction? Or should I just suck it up and let dealer keep digging into problem when their 'expert' returns next week?

 

Oh and btw, at least 2 times in past 24 hours, I have had the ABS pulsation when coming to a stop around 5mph. No warning lights were on when the pedal was pulsing, but one of the times the the svc brake warning came on about 15 seconds after. This I'm guessing would be pointing to the front hub sensors? I found the TSB on cleaning rust off sensors for rust belt regions, which I'm definitely in.

 

thanks in advance

Mike