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GM Tech (Cam)
GM Tech (Cam), GMC Mechanic
Category: GM
Satisfied Customers: 29578
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have a 2003 GMC Yukon Denali with air ride suspension. The

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I have a 2003 GMC Yukon Denali with air ride suspension. The service ride control message is on. I took it to the dealer and they said it was the compressor. I couldnt afford $850 to fix it so I bought a new compressor and dryer rebuild kit from Arnott Industries and replaced it myself. The light is still on and the compressor never turns on. Dealer said the rear shocks were most likely good but couldnt Here are the facts as I know them.

Dryer was full of water during disassembly. cleaned and rebuilt dryer with metal disc, cotton disc, dessacant, cotton disc, metal disc, new spring stack per the directions. I did NOT replace the sensor on the dryer. all orings were replaced.

New compressor was installed. During removal, there was no pressure in the line when I removed the compressor assembly.

Te service ride control light had been on fo months but not serviced as my sister said it still drove ok.

I checked 30 amp fuse under hood. It is good.

PLease help. What else can I check?

Greetings and Welcome to Just answer.

Check the Stud 1 fuse in the underhood fuse block. That fuse is the one that feeds power to the compressor. THe other fuse is for the rest of the system.

Customer: replied 7 years ago.
Is that the square one in the upper left corner of the box. Has like 2 little silver balls in it if you look straight down...CHecked is good
It is, just to be sure, can you swap it for another in the fuse block? I only ask because these can be hard to see the break, and fooled me.
Customer: replied 7 years ago.
It is good. Swapped with another 40 amp fuse (blower) and no difference and the other still worked (blower)

OK, that confirms the fuse is good.

What would help now is the code from the suspesion system. But you need a scan tool for that. All I can suggest now is check the wiring, check the level sensors and see if the are damaged.


Customer: replied 7 years ago.
CHecked the sensors and all wiring and it seems good. NO obvious damage. Dealer did not give me a code rom the scan but wrote " needs air pump for rear shocks" on my reciept. The did put the scan tool on. I assume you are talking about the scan tool for the suspension. The OBCII shows no codes. I have one of those. One more thing...when youu first start it the idle surges and fades for 30 seconds or so. That just started after I got it back from the dealer

The OBD II will only show emission codes. I Would call the dealer and ask them for the codes.

If they had the battery off, it could be relearning the adapts.

Customer: replied 7 years ago.
I will call them tomorrow. What does relearning the adapts mean? Is that where you disconnect the battery fo 30 minutes or so to clear the system? That was not done. There were two things wrong and I could only afford to fix one (front differential rebuild). Hoping replacing the compressor would fix the SRC light. Should I disconnect the battery to clear it? The rear shocks do not sag or anything like that and never have. The light is just annoying. COoul it be the sensor for the dryer? I dnt replace that. Just rebuilt the dryer

It could be the sensor, hard to say. Lets try a reset for both.

take the battery cables off and touch them together for 10 seconds, then attach them to the battery and see what happens.


Customer: replied 7 years ago.

did it. Idle didnt surge but SRC is still on...Is there a relay or something that controls power to that pump?

Yes, on the side of the fuse block under the hood is a relay, that is the one for the suspension compressor.
Customer: replied 7 years ago.
Grey - OMRON relay 12177235? DOes it sit right below where the wire harness comes out of the fuse box ?

Yes, thats the one.


Customer: replied 7 years ago.
got it out. Is there a way to test it? Pins are labeled 30,86,87,85 working clockwise from left upper pin.

Jump the termials 87 to 30 in the connector and see if the pump turns on.


Customer: replied 7 years ago.
It works!!! replace the relay?
No, not yet. The suspension module is what controls that relay. We really need the code number to know why the module is not allowing it to work.
Customer: replied 7 years ago.
I will call the dealer in the morning.

THat would be the best. With the number, I can tell you why it is not working and suggest even more tests.


Customer: replied 7 years ago.
I'll ge the code and get back with youu tomorrow. Would the compressor failing have burned out the relay? Also, my sister had been in wreck and they had to replace the dash on the car as well as drivers side mirror, ds door glass, door skin and running board. Could the body shop have done something to burn out the relay?

THe relay is not a common failing point so I doubt it.

Get the code and we will continue.


Customer: replied 7 years ago.
OK THanks
Any updates?
Customer: replied 7 years ago.
Took it to the dealer. It is the Suspension Control Module. IThey wanted $500 for one but I found the same PN out of a Caddy on ebay for $100. WIll it have to be programmed or will it just plug into it and work. They are the same exact GM part number.

IT does not have a programming, but there is a setup that is required.


Customer: replied 7 years ago.
How do you do the setup? Something I can do or does it need to go to the dealer?

IT needs a scan tool to complete the setup. THere is a chance because the module is not new that it may work, but if that does not, or it operates incorrectly, then yes it will require a TECH 2 scan tool, so a dealer or a shop that has one of these.


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