2004 GMC Yukon XL - Answered Questions & Fixed issues

Have you looked under the pas seat. Or pull the floor up at the rear where the spare tire should be

Any warning light's lit on the instrument cluster ? Check engine , reduced engine power etc...

These codes let you know the engine is running to lean on gasoline . May be only a plugged fuel filter or weak fuel pump. A vacuum leak can cause this problem . The engine controller may need reprograming with new software. Dirty fuel injectors. Try adding fuel conditioner to the gas tank and changing fuel filter.

injector/s , low fuel pressure , injector wiring , plugs , coil.s HT lead/s, distributor If used), vacuum leak, HO2S sensor , ECM , loose valve seat insert run the fault codes to find which cylinder or if random and work from there

Fuel pressure may drop due to a leaking injector or bad check valve in the fuel pump itself. The regulator does not come into effect until the engine is running and a vacuum supply is produced to it. If the regulator is leaking internally, it could send fuel back to the tank as well. Prime the fuel line and pinch off the return line ( if possible ) to eliminate a regulator problem. If the fuel pressure drops with the return line pinched off, suspect a leaking injector or fuel pump. If injector is leaking, the vehicle should run rich and cause a hard start/rough run condition

Is the selector stuck in drive? If so you might want to check the neutral switch which is on the steering column inside the truck. It sounds like you might have broken something in the switch. Hope this helps.

check the ground wire on the starter and then the battery ground

Hi Thomas , First you should have it diagnosed by someone who has the tool to do so ! upscale scan tool , factory scan tool ! Diagnostic Starting Point - Roof Begin the diagnosis with the Diagnostic System Check - Power Sunroof . The Diagnostic System Check will provide the following information: ?€¢ The identification of the control modules which command the system

?€¢ The ability of the control modules to communicate through the serial data circuit

?€¢ The identification of any stored DTCs and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located. Symptoms When no DTCs ( diagnostic trouble codes ) are present, begin symptom diagnosis by reviewing the Sunroof Description and Operation . Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Roof in order to identify the correct procedure for diagnosing the system and where the procedure is located. Important: If the suspected cause of an inoperative sunroof is a power interruption to the sunroof module, the sunroof must be re-initialized. Refer to Sunroof Motor/Actuator Synchronization . Important: The following must be completed before using the symptom tables.

1. Perform Diagnostic Starting Point - Roof in order to verify that all of the following are true:
?€¢ There are no DTCs set.

?€¢ The control module(s) can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to Sunroof Description and Operation .

Visual/Physical Inspection ?€¢ Inspect for aftermarket devices which could affect the operation of the Power Sunroof system. Refer to Checking Aftermarket Accessories in Wiring Systems.

?€¢ Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Symptom List Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: ?€¢ Power Sunroof Inoperative

?€¢ Power Sunroof Does Not Open to Express Position

?€¢ Retained Accessory Power (RAP) On After Timeout in Retained Accessory Power, if the power sunroof should operate longer than 20 minutes after the ignition has been turned OFF

This information is right out of GMC service repair manual ! Sunroof Motor/Actuator Synchronization Synchronization will be necessary anytime the sunroof module battery positive voltage circuit is interrupted. The sunroof module will be synchronized when the controller learns the full vent position. The sunroof system will ignore any open request until the system has been synchronized. To synchronize the sunroof:

1. Turn ON the ignition, with the engine OFF.
2. Using the close/tilt up portion of the sunroof switch, operate the sunroof glass until it reaches the full vent position.
3. Verify that the system operates normally.

Once the sunroof glass reaches the full vent position, the actual position is stored in the memory of the sunroof module. The sunroof module will stop the motor one motor revolution before the defined actual positions.

If u think fthe motor is ok then the cable that drives the window up and down came offits track u might have a worn out rail or the cable came off its track

Try the specified fuses in the under hood fuse center. they are common to blow.

Pull the transfer case & rebuild it

P1516 is a reduced engine power code ,check the ground wire to the head and have your throttle position sensor (TPS) tested

there will be only 1 power wire for the brake lights as they are connected .together. What you are looking at are the indicator lights (1 left wire and 1 right wire)

You can try out some guide from here reliable-store. com they also provide live chat feature for instant help and it's very useful

Short in the wiring or connector pins . Possible short in AC clutch .

Visit the on-line store, known as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem. Best Manuals

Can be done by a dealer or a shop

The computer turns on the code when the signal is received from the TPS switch on the throttle body.

Bad neutral safety switch? Engine locked?

Make sure trans fluid is full. See owners manual for proper dipstick test.