might be that relay then, it's a little bigger than a standard relay so you may have to shop around to find one, auto parts store "might" have it
07 XL Denali
- Thread starter carrmann
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
took a shot and changed out the relay with the one from autozone. compressor is still just temp connected at the harness, not fully installed. no air lines connected. it now powers on with the key for about 3-5 seconds, but does not turn on via the tech 2 scanner(exh valve responds, but nothing happens when commanding the compressor to turn on/off, no click etc). would nothing else being connected (air lines) cause this?? Or is something else wrong as well?
Last edited:
ok.
can someone at least point me in the direction to find more info on this? Googling has found me little more than what I've done, and the forum hasn't brought up much either.
recap:
my compressor is just connected to the harness NOT the air lines. it turns on with key on/start for about 3-5 seconds then shuts off. it does not turn on again after though, even when commanded to by the tech 2. I have changed the relay, and have a new 40amp fuse installed. am I missing something else?
can someone at least point me in the direction to find more info on this? Googling has found me little more than what I've done, and the forum hasn't brought up much either.
recap:
my compressor is just connected to the harness NOT the air lines. it turns on with key on/start for about 3-5 seconds then shuts off. it does not turn on again after though, even when commanded to by the tech 2. I have changed the relay, and have a new 40amp fuse installed. am I missing something else?
the red wire is for either trailer hitch power or trailer brake controller power (i don't recal which) but it is one of those, the other red wire is on the side of the fuse box nearest the fender.
and yes that is the relay for the pump, so part of the problem solved.
not sure why it's not responding to the tech2 it shouldn't matter if anything is connected to it or not it has no way of knowing the difference other than air pressure that would be there if the shock air hose were hooked up.
you might read thru the fuse listings in the owners manual and see if any of them are for the suspension or air pump and check those, I know there is at least one because there is a trick people do by disconnecting the battery and pulling a fuse to make it not see the air pump anymore making part of the errors go away,
Yea, I'm pretty confused by that considering it turns on when a few seconds after I put the key in the ON position or start it.
Thank you for the response. I'll check to see if there's another fuse I'm missing. Or relay?
Last edited:
That doesn't mean much though if you find that fuse is missing then disconnect the battery put the fuse back in and then reconnect the battery
I believe that is the self test function(powering on for a few seconds) . It wouldn't turn on at all before(relay replacement fixed it) . Figured I was making progress.
Last edited:
I said FUSES, so check FUSE # 2, 54, 58 in the underhood box.
test each one with a meter, if they are all good, disconnect the battery ground for a couple minutes, reconnect then try the tech2 again.
yea I understood. They were the first thing I checked, I'll check again though as I did not know about #2. I was referring to the fact that before nothing happened, now the self test at least was happening so I thought I was making progress lol.
There is no fuse 58. I'm looking for other fuses, I will check 2 and 54. Thank you. Already replaced 61 (Automatic level control compressor)
I looked up the ones for my 2012, so yours could be different looks like as noted 2/54/61, if you have not disconnected the battery ground I would do that as well because if all the fuses and relay is now good then it should make a good handshake with the module/bcm.
if that doesn't work then try scanning the whole system with the tech2 and see if it shows a issue with the level control module
oh ok gotcha. did all of the above. still can control exh valve, no compressor does not turn on other than for self test. I also tried raising/lowering the front and rear to see if it would trigger a adjustment (it didn't).
I did see a code for C0660 'level control exhaust valve circuit short to ground or open circuit'. last test and this ignition both say 'passed' however. I can control it to open/shut with the tech2 scanner and it works.
I'm going to grab another compressor and give that a go in case this new one is bad or wired wrong etc(I've read people getting them bad new out of the box).
I did see a code for C0660 'level control exhaust valve circuit short to ground or open circuit'. last test and this ignition both say 'passed' however. I can control it to open/shut with the tech2 scanner and it works.
I'm going to grab another compressor and give that a go in case this new one is bad or wired wrong etc(I've read people getting them bad new out of the box).
that's bizzare, i wonder if you just had bad luck and got 2 bad pumps in a row, does it work with a bench test?
Last edited:
ya, I don't know maybe check the the harness that connects to the pump and see if it has corrosion or is burnt or anything
How much current do these pumps pull? Use a fairly heavy test light (like a turn signal bulb) to load the circuit (at the connector) to see if it can pass the current and light the light brightly. Might have a bad ground or a compromised wire.
connection at the pump looks close to perfect considering 168k miles.
I'm going to try and jump the relay in the next day or two, see if it will stay running while its jumpered so I know its at least not the power wires. Also going to check the chassis module/computer (whatever that is called) to see how it looks.
No idea on the current. Thank you, I will try and give that a shot
there is a level control module also check that. it should be up under the frame in the rear, if you google a little you will see where it is located and what it looks like, should have a wide wire harness, triple row
should look just like this one
2007-2014 Tahoe Yukon Escalade Suburban Suspension Control Module OEM W/Warranty | eBay
Find many great new & used options and get the best deals for 2007-2014 Tahoe Yukon Escalade Suburban Suspension Control Module OEM W/Warranty at the best online prices at eBay! Free shipping for many products!
www.ebay.com
