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GMC Yukon / Yukon Denali



  • drabbantdrabbant Posts: 1
    I have 03 Yukon. The front A/C is not responding to my changing the fan speeds. It is stuck on a low to medium setting. It also stays on a few minutes after I turn off the vehicle. Do you have any idea what this might be?
  • frank310frank310 Posts: 44
    I had this same problem. I installed new LED tail lights on my 05 DXL and a 2 months later the right turn signals flashed constantly. I unplugged the rear tail light which plugged into stock sockets, and found rust in the connection. I cleaned the socket as best as I could in installed a regular/stock bulb and it did not work. Cleaned some more and it has worked for several months now. I still can't get the LED lights I purchased to work.
  • boricua66boricua66 Posts: 8
    My wife is on a cross country trip. She just went and put gas on my 2005 denali... It started acting up, she had it towed to the dealer and they said the gas tank was full of water. It cost me almost $350 to get it drained and flushed. Of course now the gas station is saying its not their fault. Besides their costumer representative.. who else can I contact to help me with this matter?
    Thanks in advance for any assitance...
  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,964
    The state where the gas station is located should have a weights and measures division; try complaining to them and maybe they'll investigate or refer you to some agency that can.

    Steve, Host
  • boricua66boricua66 Posts: 8
    Thank you very much Steve
  • This information applies to 2005 Cadillac, Chevrolet, and GMC Full Size Utilities with RPO JL4.

    Owners may comment on a Stability System Disabled or Service Stability message with DTC C0455. This concern may be caused by bent terminals on the SWPS (Steering Wheel Position Sensor).

    Remove the SWPS connector and inspect for bent terminals. In most cases, the terminals can be straightened without having to replace the sensor.

  • akao1029akao1029 Posts: 1
    I am in the process of buying a 03 Denali and on the list of options is says D&P and i was just wondering what does that mean/stand for. I would also like to know is there some kind on monitor on the 03's that tell you your EPA, how many miles till empty and those kind of economy things. Also I noticed that on the 02's there is a little screen above the 6-disc CD changer is that the screen that tells your EPA and what not and also how come there isn't any on the 03's and + or did they just put it somewhere else. Sorry for the noob questions. I'm new to Denalis use to have a Camaro but any help would be greatly appreciated and thanks in advance.
  • erinsquarederinsquared Posts: 178
    After about 30,000 miles, my Denali had a poor idle and would surge especially under load (i.e. A/C on). The solution to this is simple and this should be a part of your regular maintenance on the vehicle. Remove the air intake duct hose from the front of the engine where it attaches to the throttle body to expose the throttle body. Spray a throttle body cleaner generously around the edges of the butterfly valve with it closed. Now pry the butterfly valve open and spray generously. As far as I can tell, there is no separate idle circuit for this vehicle, and idle speed is maintained by the hairline opening of the butterfly valve. Problem is that blow-by oil (from pcv valve?) enters the top right of the throttle body (as you look at it) and I believe this oil cakes/coats the surface of the throttle body until it blocks some of the throttle openning - hence affecting idle. Probably should be done minimum every 30,000 miles.
  • tdohtdoh Posts: 298
    Dealer can do it (dunno if they'll charge you--probably, since you bought the wheels after vehicle purchase), or you could "invest" in a Hypertech Power Programmer III or similar (allows you to modify shift points, shift firmness, tire size, gear ratio--among other things) and do it yourself. If you want a bit more oomph out of your truck, you could look into one of the various online custom tuners that offer PCM reprogramming/retuning services--I went this route and let's just say that my DXL is definitely a bit more peppier than stock in the performance category.

    As far as brake upgrades go--depends on how much money you're willing to spend; you could spend very little by just upgrading the pads, a bit more by also upgrading to larger-sized rotors (typically requires matching pads and caliper relocation brackets as a result of increase in rotor size), and a lot more by upgrading the calipers as well (this route usually involves upgrading the entire braking hardware as a whole--caliper, rotor, pad--hence the much higher cost involved...some kits also include stainless steel braided brake lines). Myself, I went with the Baer Alumasport brake kit front and rear and it performs much better than stock, both in pedal feel and actual braking performance.
  • tdohtdoh Posts: 298
    Diagnostics and Prognostics? I dunno...EPA? I know that EPA stands for Environmental Protection Agency (among other possibilities?) but haven't seen that acronym referenced in the owner's manual as far as a vehicle monitoring system telling you your fuel economy and miles remaining until empty is concerned. IOW--I can't say I've heard of a vehicle monitoring system that tells you your "EPA".

    In any case, on '03+ GM (re?)introduced the DIC and placed (relocated?) its display right underneath the drive selector indicator in the lower center of the gauge cluster; '03 and '04 included average and instant (i.e., real-time) mpg readings, and range (i.e., estimated miles remaining until empty). IIRC in '05 GM took away the instant mpg readout from the DIC, among other things (don't know if they took away all fuel economy readouts but I do know they definitely took away the instant one).
  • mjwillsmjwills Posts: 46
    I just finally had this fixed. Dealer cleaned the throttle body and mass air flow sensor screen. They also cleaned the fuel injectors. I have 68K on mine. This did it before and another dealer replaced the throttle body. A little preventative maintenance is worth it.

    Does running a K&N filter add to the carbon/oil build up? Dealer seemed to think so.
  • obyoneobyone Posts: 8,065
    Yes it does. Worse if you have the FIPK.
  • 2005 Denali is only getting a little over 8 miles to the gallon. Seems like we live at the gas station. Our GM dealership replaced the fuel filter recently but fuel mileage isn't any better. We took it back to the shop yesterday and they said they drove it and they got 17 miles to the gallon, plus their computer confirmed it. They said they can't find anything else wrong. We know they think we are crazy but we have been keeping track of ALL mileage. Has anyone had similar problems or are there any suggestions...besides trading it off?!
  • tdohtdoh Posts: 298
    I'd be curious as to what they meant by "their computer"--did they plug in a dignostic tool, or did they go off the DIC reading? Even if they did use a diag tool, I wouldn't be surprised if it got the fuel economy readings from the same source that the DIC pulls it from...

    How many miles did they drive in order to get that 17 mpg reading? I reckon they must have gone onto the freeway or some other road where they could drive it at freeway speeds, as it is practically impossible to average 17 in city driving, at city speeds...well, not entirely impossible--one could "coast" down a city street at 45 mph for a mile and probably get a 17 mpg readout. ;)
  • dvsdvs Posts: 5
    Had this problem before with a Sonoma.
    Turned out to be some metal shavings in the Blinker switch on the column. I believe it was caused by me not engaging the blinker fully when passing a car and only pushing on it slightly enough to get the blinker to blink.

    It was not an easy task to take apart and clean out the shavings with a pocket knife but it did work. When you get it apart you should be able to see the arcing across the contacts causing the module to make a clicking sound. It did not turn on the lights because of the additional circuitry that was not made.
  • I have a 05 Denali and if the letter designation is correct the 335 hp engine is a LQ4
  • I have 22's on my 05 denali and the tire pressure reads 0 on 3 wheels and just has a dash on the 4th. The dealer told me that the sensors were not at the right angle on the American Racing wheels. I called them on it and they printed off an " internal service alert". It basically said that there were problems with aftermarket wheels that did not have the right degree of angles to bring the sensors out of standby mode. Is this the real deal or are they just BSing me?
  • arriearrie Posts: 312
    Sounds like BS to me. Of course I don't know what they mean by the 'angle' but the only thing that would make sense to me is that if the sensor is in wrong angle it would not re-charge its battery.

    The tire pressure sensor in my 2004 Tahoe has a small rattling ball or something inside that moves around with tire vibration. You can hear it if you shake the sensor in your hand. You could argue that the re-charge does not happen if the sensor is mounted in a wrong angle. Perhaps, but a failed sensor (no power in battery or otherwise broken) should give you an alarm on the dash. It should have the alarm light ON that indicates a system problem. This is different than alarm for low pressure.

    Of course the new system in '05 Denali can be different and show zero pressure even when the sensor is dead but I would highly doubt that. It could also be that the one having a dash is not working at all and the others take a zero reading until all sensors work.

    22" wheels did not come with the truck so were you present when they were put on? If the tire guys broke one sensor and didn't even tell you? It breaks easily if you don't know about it when taking the tire off or it breaks when putting a new tire on if you don't know how to do it right. This happened to me once.

    If a sensor is replaced the system must be 'trained' for it. This will not work before the new sensor is charged. It takes a couple of miles to drive with the new sensor to have its battery charged or you can shake it in your hand for a few minutes before it is installed in the rim.

    You should have instructions in your owners manual of the procedure how to teach the system all the sensors. My guess is that one of your sensors is broken or missing or is in the wheel but the system was newer set-up correctly for it.

  • Arrie

    There is a message that comes on my DIC that says "check tire pressure". I assume that I am getting this reading because of the 0 reading on 3 of the wheels. These wheels were put on by a dealer for the "our cost is your cost sale" as a little something extra to beat the competition.
    they printed up a service bulletin that was addressing the sensors not working correctly on aftermarket wheels. something to the effect that the sensors needed to be at a 45 degree angle to the ground. the sensors on my wheels are at a 90 degree to the ground. this answer suited me til i started seeing posts from several people with aftermarket wheels and no one was talking about any sensor issues. I called the dealer where i purchased the Denali and they already addressed this issue with me. Should i go see another dealer or will they just give me the colds shoulder?

  • arriearrie Posts: 312
    Have you tried to relearn the sensors in your wheels?

    If you are getting low pressure reading it means that the sensors work. The angle of the sensor should have nothing to do with that. There is just a hole through the sensor's plastic casing and pressure transmitter inside. It doesn't matter what position the sensor is to read pressure. The angle I think could have something to do with re-charging battery as that little ball (or something) inside the sensor must move for it but if you are getting a zero reading it means that the sensor works. It could be that the one with dash does not work but it could also be that this sensor was not programmed for the system correctly.

    Go through the re-learn procedure. It is quite simple to do, if it goes like in my Tahoe. It should be in your manual.

    In mine it goes:

    - Start with turning lights ON and OFF four times quickly, you will hear the horn and warning light starts blinking.

    -lower air pressure in left front wheel for about 15 seconds and you will hear the horn.

    -Move to right front and lower air pressure until horn, then do same in right rear and left rear in this order.

    This procedure teaches the on board computer which sensor is in which wheel as it sees the air pressure changing. Your procedure might be different but I guess it is the same.

    In my Tahoe if tire pressure is low I get the 'Low Pressure' warning. If I have one of the sensors out I get 'System Fault' warning.

    The different warnings and how to charge the sensor I learned when the tire guys broke one of my sensors. I carried the broken sensor in my vehicle and got the 'Low Pressure' warning for a couple of days when it changed to 'System Fault" warning. System failed when the battery in the sensor ran out and was not charged. When I took the sensor in my hand and shook it for a few minutes the 'System Fault' warning changed back to 'Low Pressure' warning obviously when the sensor started sending the signal again, which indicated low pressure in that sensor.

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