Top 10 1996 GMC Yukon Questions & Answers

I just fixed a friend of mines 96 yukon...shift to neutral press 4H and u can hear the actuator make noise (we even replaced it with a new one his idea and the same thing happen as old one), so as he hit the switch for 4H i layed under it (on 4 jack stands) and I could hear the motor on the transfer case make a loud noise (well thats working) and before all this I asked him did u check all your fuses (he said guarnteed to be all good) one night it was bothering me so i looked through the owner manual for the yukon and in the fuse box on driver side by the door there are (2) fuse for the 4wheel drive unit,pull one of the fuses good...pulled the other one and it was blown put in a new fuse and it works like brand new..pull fuse for anything that has to do with 4 wheel drive componants,

this code means your catalytic converter is below efficiency status .the o2 sensors will not fix this problem ,the ceramic in the converter is broke down ,so the converter it self is the problem.So many people think that it is a bad o2 but it is the converter!

check your dome light override switch on the dash. make sure it is not locked into the "always on" mode. check you owners manual if you need help locating it.

P0171 is a generic "system too lean" fuel code, and P0172 is a "cylinder bank A too rich" code. These are conflicting codes which suggests that a sensor is bad. Oxygen sensors are the primary component for fuel mixture determination. What I would do first though, would be to get air intake/throttle body cleaner and clean the mass airflow sensor, as it also is very important for fuel mixture control. If that doesn't work, despite the codes indicating one bank of cylinders, I would change both of the primary oxygen sensors (there is one for each bank, on the exhaust manifolds) - if one has gone bad, the other is likely not far behind. Be sure you change the ones near or on the manifolds, not the one(s) after the catalytic converters.

p1345 ckp/cmp correlation. Basically the timing is off...you can't time this motor the conventional way, you will need to find someone with a scan tool that reads camshaft position offset...the spec is 0 at 1200 prm.
P0441 EVAP emission canister purge is contolled by a valve which allows engine vacuum to pull stored fuel vapors from fuel tank into the engine to be burned, rather than be vented to atmosphere. A vacuum switch is used to detect when flow exists. If the PCM commands purge and sees that the switch is closed (indicating no detected purge flow) P0441 is set.
P1406 code, try this before you pay a shop to fix it. Remove your EGR valve and soak it in about an inch of good carbon cleaner. Dont submerge the whole thing, just the bottom part where the valve seats. Leave it overnight and clean it really good the next day with a pick and a brush. (a small screwdriver and an old toothbrush work just fine.)
Push open the valve and carfully clean any carbon built up around the valve and seat. The valve should move freely and NOT stick in the closed position. When the valve is dry, reinstall the EGR valve and clear the codes. P1406 EGR Pintle Postion Circuit
Thank you for using Fixya, you can work on the P0441 and P1406. The P1345, your going to need a scanner to set the timing.
TEST PROCEDURE
The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:

With the ignition OFF, install a scan tool to the DLC.
Start the engine and bring to normal operating temperature. IMPORTANT: Cam ****** Offset reading will not be accurate below 1000 RPM.
Increase engine speed to 1000 RPM.
Monitor the Cam ****** Offset.
If the Cam ****** indicates a value of 0°+/-2°, the distributor is properly adjusted.
If the Cam ****** does not indicate 0°+/-2°, the distributor must be adjusted.
ADJUSTING PROCEDURE

With the engine OFF, slightly loosen the distributor hold down bolt. IMPORTANT: Cam ****** Offset reading will not be accurate below 1000 RPM.
Start the engine and raise engine speed to 1000 RPM.
Using a scan tool monitor Cam ****** Offset.
Rotate the distributor as follows:
4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.
4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.

Repeat step 4 until 0°+/-2°, is obtained.
Turn the ignition OFF.
Tighten the distributor hold-down bolt to 3 Nm (25 lb. ft.).
Start the engine, raise engine speed to 1000 RPM and recheck Camshaft ****** Offset.

Sounds almost too simple but have you checked the wiring to the parking brake. If it is depressed enough to light the brake light in the dash the DRL's will not light or if the wires are not hooked up same problem. You also state you have checked the control board under the dash I assume you are talking about the Diode an aluminium finned box a little bit larger than a deck of playing cards under the dash on the right side of the steering colum at the swell in the dash. remove this diode and insert a shunt in the connector and see if those babies light up if so its the diode

It probably indicates that the cable is not being fully retracted when brake is disengaged. Spray as much of cable as possible with WD-40, allow to sit for a few hours, the engage and disengage the brake several times untill it loosens. If this fails the cable may be stretched and needs to be replaced.

It will take off from a stop in overdrive but as soon as it shifts into 3rd at about 30 miles per hour it jumps into neutral? If yes, you have a burnt 3/4 clutch. The transmission will need rebulit. Cost of about 1600 dollars.

Hi!!
Check this diagrams, in case you need additional info. just post a comment.
FRONT DRIVE SHAFT K-SERIES
FRONT DRIVE SHAFT V-SERIES

FRONT SUSPENSION DIAGRAM

INSTALLATION OF DIFFERENTIAL CARRIER

INSTALLATION SHAFT SEAL

LEFT SHAFT DIAGRAM

the fuel filter is located under truck on left frame around middle of truck