GMC

GMC troubleshooting questions? Ask a mechanic for answers

Ask an Expert,
Get an Answer ASAP!

2005 Envoy Denali. Replaced Air Suspension Compressor with…

Customer Question
2005 Envoy Denali. Replaced Air...
2005 Envoy Denali. Replaced Air Suspension Compressor with identical part. Compressor turns on with manual inflation switch but does not pump up airbags when starting the vehicle. Power supply is good, ground is good, all fuses checked and are good. Doesn't seem to be sending any voltage to either leveling sensors. What am I missing?
Submitted: 2 years ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Answered in 6 hours by:
2/24/2016
GMC Mechanic: Christopher Trevino,
 replied 2 years ago
Christopher Trevino
Category: GMC
Satisfied Customers: 7
Experience: Field Service Technician at Crown Lift Trucks
Verified

Hello, I saw your question going unanswered and I wanted to assist you here. I've fixed a similar problem on a Cadillac Escallade, These systems tend to be similar, I wanted to see if I could help you here. Is your Denali giving you a "SERVICE RIDE CONTROL" or "SERVICE AIR RIDE" on the DIC display in the instrument cluster? If so you will need to use a certain type of scantool that will communicate with this ESC module to see what codes are active or stored in the module. The module closes the ground for the ALC relay circuit to power the compressor. If you can post the codes here , I can continue to assist you here. Thank you,

Ask Your Own GMC Question
Customer reply replied 2 years ago
No error messages on instrument panel regarding air ride system. I do have a "service airbag" message but I'm pretty sure it's referring to the actual SRS because the "bubble gum guy" light is on as well. Also, the air compressor manual switch has a light on it. If there are malfunction codes it's supposed to flash with 1 of 3 sequences depending on the code. It doesn't flash at all, so no codes. I just pulled the automatic sensor plugs and tested them. I'm getting 3 ohms of resistance coming in (sent from compressor) and nothing coming out, which to me would indicate the signal from the compressor is good. I had the same problem with the previous compressor which I thought the problem was but I'm having the same issue even after I replaced it with a new one. Ironically, from time to time that compressor would kick on and fill the airbags. After time, the truck would start to sag and the compressor would not be triggered. It's an intermittent problem. I removed and cleaned the ground to the vehicle frame because I suspected that could be the issue but not to my surprise it wasn't. I'm stumped.
GMC Mechanic: Christopher Trevino,
 replied 2 years ago

Ok got it , thank you for the details. take a look at the wiring diagrams I have posted here, If you can post the diagrams you have I'll compare the two. Here's what I got for an 04 Escallade ESV. If I cant help you here I'll re-submit your question so hopefully a GMC Tech can further assist you. I Just want to make sure you get taken care of first and foremost!

cf14cc74-5808-4fa7-8b03-...gifcf14cc7...gif9e8ce99c-5628-4616-99ce-...gif9e8ce99...gifaa1410f6-36db-4e50-a1f3-...gifaa1410f...gif
Ask Your Own GMC Question
GMC Mechanic: Christopher Trevino,
 replied 2 years ago

I got it , thank you. Have you tested resistance from the other side of the plugs from the level sensors. not the harness to the module , but the sensors themselves? I just wonder if they are open or shorted, 0.2 ohms would be shorted and OFL would be electrically open as I'm sure you already understand. Also, if you have the electrical pin breakdown for the compressor would help. If the exhaust solenoid fails , it shuts down the compressor as well. However manually closing the switch closes the ground to power up the compressor. You are pretty much doing what the module should be doing but it cant because its not getting the correct inputs from either the steering sensors (if applicable ), level sensors, exhaust solenoid ect. I"d like to see what codes are present , The SRS codes may also interfere with this operation. I would start ohm testig the level sensors and any component possible related to the compressor for opens or shorts, then if still inconclusive , scan all the codes present on the truck to see what the module is seeing and that should guide you in the right direction.

Ask Your Own GMC Question
Customer reply replied 2 years ago
In the schematic I sent you, there are 2 plugs. 1 has 8 pins labeled A-H and the other has 3 A-C. I haven't tested the resistance on the sensors themselves because if they were bad I'm supposed to get either the service air ride message and/or the blinking light on the manual air switch. Also, if one goes bad the vehicle reads off the working sensor for both sides, but then again, it's supposed to show a fault that a sensor is not relaying feedback. I've test the exhaust valve, it works. The end of the exhaust line is located next to the manual air switch and I can here it exhaust when I manually turn the switch off and on. What I'm trying now is, I jacked up the body to what is called "D Height" and am resetting the ecu to try to get it to recalibrate or learn the height to see if that works. Being that the vehicle is sagging very low I'm hoping that once I lower it, the recalibration will trigger the compressor and fill the bags.
GMC Mechanic: Christopher Trevino,
 replied 2 years ago

That sounds like a plan, next chance you get , with all the connectors plugged together , back probe points H and D you should get 12volts. and with the key in the run position, points G and D you should get 12 volts. By the way, you don't happen to be in any freezing weather conditions? Freezing temps seem to lock the compressors up. Usually below (25deg). Let me know how it goes, ill check back tomorrow. Best of luck!

Ask Your Own GMC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a gmc mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Gm Tech (Cam) Your Own Question
Gm Tech (Cam)
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 1,815
1,815 Satisfied Customers
Experience: GM Grand Master Technician 2007. 14 year experience.

Gm Tech (Cam) is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Gm Tech (Cam)

Gm Tech (Cam)

GMC Mechanic

1,815 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

1,588 satisfied customers

GCM master tech over 25 years

Dave Nova

Dave Nova

GMC Technician

929 satisfied customers

ASE Master Certification. GM World Class Certification

Chris (aka-Moose)

Chris (aka-Moose)

GMC Technician

626 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

279 satisfied customers

18+yrs experience. State Inspector & GMC Diagnostics/Repair

JFN1

JFN1

ASE Certified Technician

270 satisfied customers

GM Master Technician

George H.

George H.

ASE MasterTechnician

228 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

< Previous | Next >

Related GMC Questions
2008 Yukon Denali air ride compressor doesn't start, no
2008 Yukon Denali air ride compressor doesn't start, no message or error in info center, changed compressor, relay and checked all fuses. I hear one click noise in the compressor, old and new alike bu… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,815 satisfied customers
I have a 2001 yukon denali xl and having a problem with my
I have a 2001 yukon denali xl and having a problem with my air ride system. I have check all fuses and relay and the compressor is new. When I turn the key (but not starting the engine) after about 10… read more
Danny
Danny
Owner, lead mechanic
High School or GED
3,963 satisfied customers
Auto ride compressor wont work. 2011 yukon xl denali. Found
Yes, found rubbed wires on the frame rail going to compressor, and replaced the compressor. I turn the key and I hear a click at the compressor but nothing happens. … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
2002 gmc yukon denali xl air ride problem. New compressor
2002 gmc yukon denali xl air ride problem. New compressor assbly, still won't turn on. Checked all fuses,good. How do I check the actuators for the rear wheels? … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
5,594 satisfied customers
Service Ride Control" message is showing. Noticed compressor
Service Ride Control" message is showing. Noticed compressor doesn't come on when I load the vehicle. For starters, is there a fuse I can check to see if its something that simple? … read more
Dan
Dan
Dealership Technician
Associate Degree
2,145 satisfied customers
I am working on my 2005 GMC Envoy with air springs in the
I am working on my 2005 GMC Envoy with air springs in the rear. Yesterday I noticed that then springs were no longer pumping up. The compressor runs for a minute or so and then shuts off . If I restar… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
I have an 07 yukon xl denali I have replaced the air ride
I have an 07 yukon xl denali I have replaced the air ride compressor both rear air shocks rt front level sensor and I'm still getting the service suspension in the dic the code showing on my scanner i… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I have a 2006 gmc envoy xl. Had new air bags installed 6
I have a 2006 gmc envoy xl. Had new air bags installed 6 months ago and now the dealer tells me the compressor has gone out. i pulled out the compressor. I am wanting to check it to make sure its the … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
I've got a 2002 GMC ENVOY and it's got problems' with the
I've got a 2002 GMC ENVOY and it's got problems' with the rear suspense air pump..when you turn on the key the pump will come one but won't inflate the airbags and continue to run for around 45 second… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Gmc envoy: I have a 2002 GMC Envoy SLT and the Suspension Air
I have a 2002 GMC Envoy SLT and the Suspension Air Pump for the rear air ride bags does not come on and the air bags won't hold up the rear of the vehicle. I also have an auxilary air inflation port t… read more
Daniel Jones
Daniel Jones
High School Diploma
476 satisfied customers
2007 GMC denali envoy .replaced leaking cracked air bags rear
2007 GMC denali envoy .replaced leaking cracked air bags rear .right one is getting enough aire to get hard , left bag gets no air . moved levelers manually , right one reacts when moved , left one do… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
GM envoy slt: I have a 2004 envoy with a load level system
I have a 2004 envoy with a load level system I have replaced the 2 air coil springs can this be a adjusted for height compressor is good coils do inflate but not to proper height any help would be a a… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
GM Yukon Denali: My 2005 GMC Denali has new Arnott air shocks
My 2005 GMC Denali has new Arnott air shocks on the rear with a new compressor as well. Compressor comes on at each start for about 4 seconds but doesn't inflate the shocks enough to engage a full sea… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
GMC Envoy: I have a 2002 EnvoyXL. The drivers side air suspensio
I have a 2002 EnvoyXL. The driver's side air suspension seems to be inflated all the way. The car is tilted towards the passengers side. I removed the two air lines from the top of the compressor unit… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,815 satisfied customers
GM Envoy Denali: Hi - I have a 2006 Envoy Denali and every
Hi - I have a 2006 Envoy Denali and every time I come to a stop for more than 8 or so seconds the rear suspension lowers and then pumps back up within 3-5 seconds. Other than that, it seems to work wh… read more
mike a mechanic
mike a mechanic
Auto Mechanic
Vocational, Technical or Trade Scho
89 satisfied customers
GMC Envoy XUV: Can I change the check valve on the rear suspension
Can I change the check valve on the rear suspension compressor without removing it?? PN 15183676. Is there a thermal relief valve?? My car settles much faster when it is hot out. Is there a schematic … read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC Envoy SLT: I have a 2005 GMC ENVOY .The rear suspension
I have a 2005 GMC ENVOY .The rear suspension does not stay up at times when parked. It seems to depend where it is parked .If on level ground it stays up if on a downward slope it sinks . My question … read more
tripletauto
tripletauto
Shop Foreman
Associate Degree
140 satisfied customers
GM Envoy XUV: I have a minor leak in the air bag suspension
I have a minor leak in the air bag suspension on my 04 Envoy XUV. That I can deal with but starting yesterday it doesn't always start the compressor and fill the system. In the last five starts it has… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,815 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x