Automatic Transfer Control Fuse

[BigSilver]

Anyone know where the ATC fuse is located, on a 2003 Chevy Suburban,

2500, 6L? Its supposed to be under the hood, so I checked the fuse

box, but there's nothing there.

[silveradobobby]

Check the fuse panel on the driver side dash, open door its in the corner of the dash.

[BigSilver]

Check the fuse panel on the driver side dash, open door its in the corner of the dash.

 

Thanks for the reply. The only related fuse at that location is marked 4WD. I guess

GM used different markings. A snapshot of the fuse layout pattern follows

and there is no ATC fuse.

[silveradobobby]

Whats the problem your having?

[BigSilver]

Whats the problem your having?

The 4WD transfer control switch just went dead.

No indication weather the Burb is in 4Auto, 2Hi,

or 4Lo. Up until now, only the encoder motor was

glitched and the transfer case would operate

in either 4Auto or 4Lo, depending on which

button was depressed.

[silveradobobby]

Sounds like the switch its self went south is happens all the time on your year.

[BigSilver]

Sounds like the switch its self went south is happens all the time on your year.

 

Perhaps the switch packed it in, but the T2 is experiencing difficulty

with communicating with the Burb's OBD.

BTW, what would be the part number for the switch?

[BigSilver]

Sounds like the switch its self went south is happens all the time on your year.

 

Perhaps the switch packed it in, but the T2 is experiencing difficulty

with communicating with the Burb's OBD.

BTW, what would be the part number for the switch?

 

 

Well, after extensive searching on the net, I found out that there is no specific fuse in the fuse box that is labeled as an ATC fuse. (As it happens, all fuses of the metal tabed variety are reffered to as ATC fuses, by fuse manufacturers).

 

The GM shop manual obviously errored relating to the 4WD switch to a fuse supposedly labeled as an ATC fuse, when only a TREC fuse (30 amp) exists under the hood within the fuse box for this application. This fuse distributes power to the 4WD switch amongst other related circuits. After checking my TREC fuse, I found it to be burned out. So I replaced it with a new 30 amp fuse and voila, the 4WD switch became active again.

 

So what caused the fuse to blow in the first place? A good question in itself. This issue eludes the GM shop manual. Could it be related to a faulty 4WD switch? Maybe. Could it be related to the buggered encoder motor sensor on the transfer case? Maybe, though not likely, as its been in defect mode for over 5000km (3000+miles) and this is the first time the fuse burned out. The mystery continues, in the meantime, equip yourselves with a spare 30 amp TREC fuse and save a bundle on switch replacement.