You might check the speed sensor on the individual wheel hubs too even if one of them isnt working your speedo can still work(personal exp.)

 

I had the same issue just yesterday. I went on a long trip that totaled about 1600 miles and when I got back the next day all of my ACD lights were on. I read this post and a few others but I just took it to the dealer. After they ran a check I threw three codes... 1) ACD pump failure 2) ABS failure 3) back rear left speed sensor failure

I live out in SoCal and I had Rigo at SCM check out the car. He checked the speed sensor and made sure that no metal got caught up in it to throw it off. Plus he also checked my ACD pump to make sure it was not dead. Thrid I think that because of the ACD pump failure code.. ABS will throw a code to be checked also.

Resolution: I had them redo all of the drive line fluids ... (to make it worth while for pulling the codes..) plus this will help to take out any guess work towards old fluid being the issue. Right now the lights have not come back and I plan on washing the hell out of the car to make sure 2000+ miles of break dust are not killing the speed sensor ( I didnt wash my car before I went on the road trip).

I hope this info helps somebody.....

 

well yday i had my car parked with the hood open facing the sun btw it was 85degrees.. so i took it for a drive then after about a 1/4 mile all 3 light turned on and when i shut that car off and turn it on again they are off till about another 1/4 mile of driving again. but this does not happen everything all the lights wont go on everytime i drive, so does anybody have input to my problem befor my dealer charges me 75 just to do a diagnostic check????

 

lucky. my dealer is charging me $100 to diagnose mine. yay. and it's 20mins out of town (local dealership went out of business). AND i gotta find a ride back home. THEN a ride out to get the car. no bueno.

 

sh|t mine is having the same damn problem. maybe i just need to change the transfer case oil since i haven't done so yet.

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