service 4wd

i have a 2005 avalanche with the dreaded service 4wd , i have already changed the switch in the dash and same problem ,now it has no lights on the dash and i stopped at a stop light went to take off and now i am in 4wd low had to pull into a parking lot and restart the engine and then no lights but made it home... i am afraid to drive it to far because i dont know if it is going to hurt anything
thanks :frown:


any help would be appreciated

Most likely you have a code c0327 stored for a failed encoder sensor. Without a code scan you wont know for sure. The sensor is inside the encoder motor and can be serviced separately or it comes with a replacement motor. The motors are a little pricey though.

i have a 2005 avalanche with the dreaded service 4wd , i have already changed the switch in the dash and same problem ,now it has no lights on the dash and i stopped at a stop light went to take off and now i am in 4wd low had to pull into a parking lot and restart the engine and then no lights but made it home... i am afraid to drive it to far because i dont know if it is going to hurt anything
thanks :frown:


any help would be appreciated

have the gm drive train codes posted here. problems like this can be many things. the switch with bad solder joints ,bad / wrong transfer case fluid,wires damaged from rodents or mechanics. the encoder motor position sensors do get damaged over time with bad fluid/wrong fluid.

post the fluid color and condition . should be blue if black you may need a new/re-build..

i have a 2005 avalanche with the dreaded service 4wd , i have already changed the switch in the dash and same problem ,now it has no lights on the dash and i stopped at a stop light went to take off and now i am in 4wd low had to pull into a parking lot and restart the engine and then no lights but made it home... i am afraid to drive it to far because i dont know if it is going to hurt anything
thanks :frown:


any help would be appreciated

Hello ckt1965,

Looks like you're having trouble with your dash lights, and I apologize for this experience. If you're thinking you'd like to have a Chevrolet certified technician take a look at this, we'll gladly contact them on your behalf. If interested, please send your VIN, mileage, contact information, and preferred dealership in a private message.

Kind regards,

Jasmine
GM Customer Care

I had this, when I first got my truck home after purchase (used) I changed the TRANSFER CASE FLUID to Valvoline. On the bottle it was stated that it met all the latest needs so OK! Well it didn't. I then changed it to AC Delco's blue stuff. I had to buy it at the dealer at $12.++ per quart. Pricy but guess what? No more messages!

I am back again and now I am getting ABS light as soon as I go forward 2ft. I don't have any braking issues but it worries me to go long distances.



thanks for any info on this issue

Without scanning for error codes, diagnosis will be more difficult. Since the system replies upon the speed sensors in the transfer case to determine wheel travel, it is important that the sensors in the case are clean and intact. The system also uses the front wheel speed sensors as inputs, so those are also important. The speed signal sensor outputs can be checked with an AC voltmeter.