Jump to content

2001 Suburban auto ride compressor deep dive troubleshooting

nvetro

Recommended Posts

nvetro New Member

nvetro

Posted
Posted

I have a 2001 Suburban 1500 LT with the auto ride rear air suspension. On my last trip towing my 22' Hallmark inclosed trailer I noticed the compressor did not kick on when tongue weight was adding which of course caused the rear to sag.

Thinking it had to be the compressor since searching the web focused on the compressor (namely the exhaust solenoid) going bad. I went to CarQuest and picked up a new compressor and installed it and the compressor STILL did not kick on even with tongue weight. I do not have a service ride suspension indicator on my dash (this is likely because I am having a Suburban 2500 dash because I wanted a trans temp gauge and maybe this alert is disabled). I also do not have any codes stored when I used my scan tool.

I applied power and ground to the compressor connector and it ran and applying power to the exhaust solenoid leads on the compressor made it click, thinking MAYBE I got a bad compressor I returned it and got a new one, of course this did not fix my problem. I went a step further and applied power to Pin 30 and Pin 87 of the ALC relay under the hood which should trigger the compressor to go on, this did NOT work and I tested pin 30 was showing 12V just fine and the jump to 87 was working.

Other things I've checked are the IGN3 fuse (inside), Stud #1, and the RDC fuse under the hood, all came up fine. I also tested that there is 12V power at the connector which connects to the compressor (both the 12V main lead and the power lead that goes to the exhaust solenoid. When I stand on my hitch I hear a click coming from the compressor area, which I bet is the exhaust solenoid perhaps.

Anyway, I've checked everything I know and from searching forums. The harness looks in good shape as do the ride height sensors, could I be looking at a bad SCM (Suspension Control Module)? Thats the unit behind the right rear plastic in the trunk. The WEIRD part is when I jump pin 30 and 87 on the ALC relay the compressor doesn't come on, would a bad SCM cause this since I assume power runs through that unit?

Please help :-)

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted

I have a 2001 [/size]Suburban 1500 LT with the auto ride rear air suspension. On my last trip towing my 22' Hallmark inclosed trailer I noticed the compressor did not kick on when tongue weight was adding which of course caused the rear to sag. [/size]

 

Thinking it had to be the compressor since searching the web focused on the compressor (namely the exhaust solenoid) going bad. I went to CarQuest and picked up a new compressor and installed it and the compressor STILL did not kick on even with tongue weight. I do not have a service ride suspension indicator on my dash (this is likely because I am having a Suburban 2500 dash because I wanted a trans temp gauge and maybe this alert is disabled). I also do not have any codes stored when I used my scan tool.

 

I applied power and ground to the compressor connector and it ran and applying power to the exhaust solenoid leads on the compressor made it click, thinking MAYBE I got a bad compressor I returned it and got a new one, of course this did not fix my problem. I went a step further and applied power to Pin 30 and Pin 87 of the ALC relay under the hood which should trigger the compressor to go on, this did NOT work and I tested pin 30 was showing 12V just fine and the jump to 87 was working.

 

Other things I've checked are the IGN3 fuse (inside), Stud #1, and the RDC fuse under the hood, all came up fine. I also tested that there is 12V power at the connector which connects to the compressor (both the 12V main lead and the power lead that goes to the exhaust solenoid. When I stand on my hitch I hear a click coming from the compressor area, which I bet is the exhaust solenoid perhaps.

 

Anyway, I've checked everything I know and from searching forums. The harness looks in good shape as do the ride height sensors, could I be looking at a bad SCM (Suspension Control Module)? Thats the unit behind the right rear plastic in the trunk. The WEIRD part is when I jump pin 30 and 87 on the ALC relay the compressor doesn't come on, would a bad SCM cause this since I assume power runs through that unit?

 

Please help :-)

Did you have the truck SCM scanned before guessing anymore ? Hmmmm ?

 

Get alldata .com and SLOW DOWN BIG SPENDER !!!

nvetro New Member

nvetro

Posted
  • Author
Posted

I was trying to avoid bringing the truck to the dealer because I bet al their going to say is bad compressor and change me $200 to tell me something wrong.

 

Any other DIY things I can test? I'd rather get a new scm on eBay for $125 before throwing money away at the dealer

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted

You can guess or do it right , your choice,

 

Why not spend money smartly instead of guessing?

 

You've been burnt already from guessing

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,897
    Total Members
    8,960
    Most Online
    ncleg
    Newest Member
    ncleg
    Joined

  • Who's Online   4 Members, 0 Anonymous, 693 Guests (See full list)

  • Latest Articles

  • Posts

    • XY74
      Roll up bed cover experiences

      By XY74 · Posted

      I have a Retrax pro that I first had on my 2020 chevy and transferred it to my current GMC.  It stays in the garage most of the time, so hard for me to judge it's long term weather resistance.  It still works perfectly, been very durable.  It doesn't see oil patch usage, but it's not a mall queen.  It keeps most things mostly dry (small leaks) and the security of it is enough to slow someone down but not keep them out for long.  I would buy one again, it works for me.     
    • fm2176
      New to Me 2010 SLE (Quirks, Issues)

      By fm2176 · Posted

      Thanks to the convenience of Amazon, I was able to get a few things done to the truck today.  I installed Carquest Premium oil and air filters with five quarts of Mobil1 High Mileage 10-30 along with a quart of Pennzoil Platinum 5w-30 I already had.  The latch for the flip up center console lid was broken so I replaced it along with the power mirror switch.  I found my push retainer assortment this morning and reattached the plastic under the bumper and it was only held on with a few screws and retainers.  Then I programmed a new remote keyless entry fob so I can lock my dog in the truck when I take her out with me (I've got to keep the air going for her since it's been in the 100s).  Finally, I ordered some LED interior bulbs and replaced the reading lamps.  The front lights are working fine while one of the back lights only works intermittently and the other not at all.   While under the truck, I found the source of at least one of the noises: the sway bar links need replacing.  I ordered a set of Suspension Dudes links with Code Red bushings.  Never heard of them, but they're made in the USA and have decent reviews.  While making yet another Amazon order, I went ahead and added a set of front tow hooks.  I went with red, since that's the color of the sway bar link and bushings and it should look decent enough on a black and chrome truck.  Speaking of which, it doesn't bug me much, but the passenger side mirror has a chrome cap while the driver side doesn't, so eventually I'll make them match one way or another.  Oh, and I ordered a $20 TPMS reset tool.  No idea if it will do anything for my sensors but it was cheap and will work for the Ford Transit Connect as well.     For tradition's sake, I ordered a new oil change wrench.  I kept the Snap-On 9/16"x15mm GM wrench I bought when I was 18 in the 2006 GMC from the time I bought that truck until the truck was lost.  While I was tempted, there's no need to spend $80 for a new SO wrench, or even $50 with shipping for a used one on Ebay.  I just bought a Duratech 15mm extra-long ratcheting wrench to do the job as needed.  It works, and if I like that wrench enough, I'll buy the set.  
    • Another JR
      Multigate electrical problem

      By Another JR · Posted

      The recall is for exactly this issue - those drain holes combined with the limited environmental capability of the tailgate electronics card inside the tailgate were a problem. The “safety issue” was the potential for the tailgate to spontaneously open, but all kinds of tailgate misbehavior can occur from water contamination of that control card.    There is no real fix yet. The initial recall just disabled the tailgate. Later, when parts became available, they would replace bad parts with new parts of the same bad design. My dealer is going nuts because the few times I let them get their hands on my truck, my tailgate is off due to a slide-in camper installation. They really want to cut my tailgate wires, but I won’t give them the chance. I will let them get their dirty hands on it when a real fix (redesign) is available.  My tailgate, which works just fine with sealant plugging the drain holes, will remain safe in a dry storage crate until then.  
    • JakeD
      Tire fitment

      By JakeD · Posted

      Yes your absolutely right, I been looking at the 4 inch BDS one and it acutely states you can use the stock 20’s just not the 17’s or 18’s, I also didn’t realize that with my 275/60r20 stock wheels I’m already running 33 inch diameter wheel setup lol so I can just run my stock wheels and tires atleast to start.
    • davester
      Tire fitment

      By davester · Posted

      I would expect that to be lift-kit dependent.  If the kit has interference issues w stock wheels, then the kit/manufacturer should indicate that somewhere.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...