Question about GMC Cars & Trucks
Two speed automatic or is it two speed selectable ? Either case the first thing would be have it check for DTC'S - diagnostic trouble codes . Both are computer controlled .
DTC B2725 ATC Mode Switch Circuit Malfunction
DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0323 T-Case Lock Circuit Low
DTC C0324 T-Case Lock Circuit High
DTC C0327 Encoder Circuit Malfunction
DTC C0362 4LO Discrete Output Circuit High
DTC C0367 Front Axle Control Circuit High
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0387 Unable to Perform Shift
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error
This for the two speed selectable
The transfer case shift control module normally has battery voltage supplied to it at all times through the battery positive voltage circuit (CKT 40). When the ignition is ON, the transfer case shift control module conducts a self-test to determine if it retains the same memory it had when the ignition was last turned OFF. This self-test indicates whether the RAM standby power supply to the transfer case shift control module pin C6 was interrupted, which would result in clearing DTC's from memory. If the self-test fails the transfer case shift control module sets DTC 1.
You can check codes without a scan tool on this two speed selectable system . Do you know what the DLC is ? Under the steering wheel , connector to plug a scan tool into ?
Important: Check the transfer case shift control module for DTCs. The transfer case shift control module is not a class 2 device. DTCs are displayed on the transfer case shift control switch. Use the following four steps to obtain DTCs.
Turn OFF the ignition for 10 seconds.
Connect PIN 13 on the data link cable (DLC) to a ground. The DLC is located in the cab under the instrument panel on the driver's side.
Turn ON the ignition, with the engine OFF.
Observe the transfer case shift control switch select buttons for flashing codes.
Posted on Dec 30, 2016
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Gently pop off the horn cap / cover.
There will be a short wire attached, so be careful not to pull it too hard.
You will see the wire going into the metal frame of the steering wheel.
The wire will go into a "sleeve". Push the sleeve in, and turn slightly counter-clockwise to unlock the connector. The horn will beep a few times as you pull the wire out, just to warn you :)
You will now need a steering wheel puller. These can be bought for about $10 at any auto parts store.
Once the wheel itself is off, you will see a black plastic disk. remove it. Now you will see a metal disk with notches in it (this is what locks the steering wheel when you turn the key off). You may want to get someone for assistance for this one, as there is a pretty stiff spring behind the disc, so use caution. You will need to push the disc towards the dash and remove the retainer clip.
Once that is off, you will see the white turn signal switch. Remove the hazard switch button first, then the turn signal lever retaing screw (be careful if it has cruise control, as the wires are thin and delicate), then remove the 3 phillips head screws holding the actual switch on. Let the switch hang out of the way.
Now, you'll see the lock cylinder retaining screw. This is where you may have a problem if you don't have a key.
After removing the screw, you MUST turn the ignition switch to the "run" position and pull out the assembly.
Posted on Jun 19, 2008
SOURCE: '03 GMC 2500HD 4x4 problems
Take your positive cable off battery and wait a few minutes..This resets the computer and takes it out of limp mode.Theres been a lot of problems in the dash so if you can find an auto zone and have them scan it They'll do it for free.But as far as the lights my truck does the same thing. Just flick your fingers on the buttons and they should flash..The plug in the back of buttons was loose..
Posted on Mar 29, 2009
Use the Owner's Manual to manually go into neutral and reset to 2WD HI. But then look under the hood check the fuses or look for wiring that may have come unplugged.
Posted on Nov 19, 2009
I own a Jimmy and have done quite a bit of 4 wheel drive repair on it.
The first thing i would check is the 4x4 selector switch. I know for a fact that these will throw a service 4x4 code if they are unplugged or shorted. They sell for 50-60$ or you may find one at a local salvage yard for cheaper. Taking this out and checking it only takes a few seconds, just simply pop the switch out of the dash with the edge of your pocket knife. After you get it out theres a few more tabs surrounding the back plate, and this is where the circuit board is located. I would inspect it visually to make sure nothing looks corroded and also take a sniff of it to insure there isn't a burnt smell. If it were the 4x4 actuator the lights would still illuminate on the selector switch, it just wouldn't engage the 4x4. You'r problem is all electrical trust me .
Posted on Jan 05, 2010
Tips for a great answer:
Sep 29, 2014 | 2000 GMC Jimmy
these issue, there are few solved help links for troubleshooting the
the link below: ---
control switch will not engage on 4WD High or Low
flashing and 4WD will engage after few minutes
details will help.
Nov 28, 2012 | GMC Cars & Trucks
Oct 26, 2012 | 1999 GMC Jimmy
May 06, 2017 | 1995 GMC Jimmy
Feb 08, 2010 | 2000 GMC Jimmy
Nov 25, 2009 | 2001 Chevrolet Silverado 1500
Nov 23, 2009 | 2000 GMC Jimmy
Aug 13, 2009 | 1999 GMC Jimmy
Jun 19, 2009 | 2000 GMC Jimmy
50 people viewed this question
Usually answered in minutes!