Chevy Cowboy

iTrader: (5)

the other day I went to drive out the driveway and it was coated in pure ice, and it just spun in 2wd so I put it in auto 4wd and I tried getting out and still couldnt and I thought that was really weird so I rolled down the window and looked out watching the front tires, and they werent moving. I then proceded to try 4hi and the light would blink and blink then go back to 2hi. I QUICKLY tried cleaning the ground wires on the frame below the driver side cab, didnt help. Being in a hurry my dad just gave me a little push and I got out in 2hi so about 10 minutes later driving I decided to try it again, hit the 4hi button and it went right in like it always use too, so i thought it was just cold. Anyways I got home and it was still working then, and went out later again that night and it wasnt working, even the little lights were not on, next morning i started it up to see if it would work, started it up and the little lights were on so I said cool but weird, got home tonight tried it again, the little lights were NOT on again! and service 4wd light was on again, soo is it the switch or bad ground or????


sorry for the super long badly punctuated paragraph

DrX

iTrader: (7)

Is DTC B2725 set? Found this service Bulletin for 99-02 trucks.

Service 4WD Indicator Illuminated, DTC B2725 Set (Replace Transfer Case Shift Control Switch) #02-04-21-004 - (Apr 15, 2002)

"Service 4WD" Indicator Illuminated, DTC B2725 Set (Replace Transfer Case Shift Control Switch)
1999-2002 Chevrolet and GMC C/K Pickup and Utility Models (Silverado, Sierra, Avalanche, Suburban, Tahoe, Yukon, Yukon XL)
with Four Wheel Drive and NVG 236/246 Transfer Case (RPO NP8)

Condition

Some customers may comment on the Service 4WD indicator illuminating. Upon investigation, the technician may find DTC B2725 set.

Cause

The condition may be due to a intermittent fault in the transfer case shift control switch.

Correction


Important

The transfer case shift control module should not need replacement. DO NOT replace P/N 15749703 unless diagnosis points to the module as the malfunction.

Replace the transfer case shift control switch using published Service Information procedures.

Parts Information

Part Number
Description
15709327
Transfer Case Shift Control Switch

Chevy Cowboy

iTrader: (5)

ok Ill get it scanned today or tomorrow and hopefully its just the switch, it should be alright to drive my truck tell then eh?

Torque_Wrench

iTrader: (13)

tHE EASIEST WAY TO TELL...IS IF YOU LOOK AT IT AND IT'S BLINKING A YELLOW LIGHT IN 4WD OR IF YOU HAVE A RED LAMP ON IN THE NEUTRAL POSITION. THIS SWITCH GOING BAD IS PRETTY DAMN COMMON....I KEEP A GOOD ONE IN MY DASH POCKET AND AT LEAST 2 GOOD ONES AT HOME.

Chevy Cowboy

iTrader: (5)

hmm, I just got home and the entire way home, it said service 4wd and none of the yellow or the red lights were on, but in the mornings when I start it up the yellow lights will be on but I hit the 4wd button and it will not go in, it will blink on 4wd for a few seconds then go back to 2wd, same with 4 low, the yellow light will stay on auto 4wd if i hit the button but the auto 4wd does not actually work?? I bored a cousin OLD snap on scanner and it didnt show any codes for the 4wd, were pretty sure it just cant access that deep into the system?? but it did show one other code U1026 heres what troublecodes.net said about it

SCP (J1850) Invalid or Missing Data for Engine RPM , what the hell is that? Would that have to do with my truck starting weird? I hold the key and it turns over for like 2-3 seconds makign a clicking noise then starts?

Should I go and get the GM techs with the tech 2 to scan it?

Man Im getting pissed at this truck....

THE-HOE

iTrader: (3)

My tahoe dID EXACTLY THE SAME THING. but i found a wire broke under the electrical center. i put it back together and all my problems were solved. but thats probably rare that that could happen.

Chevy Cowboy

iTrader: (5)

I almost hope its not a broken wire, I dont like searching for broken wires, under the electrical center is refferring to where? under the fuse panel under the hood? Cause if thats where your refferring to that could be it, I recently did the 4 high mod about 2 weeks ago, and I did it the way where you splice into the 1 yellow wire under the fuse panel....maybe I cracked a wire or something? and the wet weather lately corroded it??

Also what wire was it that broke on the hoe?

THE-HOE

iTrader: (3)

yes, thats the place that im talking about... and hmmm im thinking it was a little pink/or light red one. this happened about a year ago so its hard to remember... Im thinking yourse wouldnt be this problem because sometimes you have it and other times you dont. But whats the 4 high mod? ive never heard of it

Chevy Cowboy

iTrader: (5)

ok Ill check for broken wires just to be safe, the 4 high mod allows your low beams to stay on when you flick to your high beams, giving you alot mroe light, you just have to splice into a yellow wire in your electrical center and ground it

Chevy Cowboy

iTrader: (5)

did a search on my trouble code, apparently it means theres a loss of communication with my transfer case, I may need a reflash, a new module or there is a bad connection at the transfer case. Hey torque wrench how much is a new module?