Air suspension pump will not turn on and when accelerating from a stop there is a loud popping noise coming from the front differential

2002 CADILLAC ESCALADE
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RODNEYNME
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My SUV listed above is an awd 6.0. Dealer say both problems listed above maybe caused by ABS. I don't here it when I turn left or right. I have no codes showing up on dash I bought an Innova 3160b ABS -SRS obd2 scanner and pulled no codes from ABS or any were else. So far for differential I pulled it out and mechanic took it apart said they seen nothing wrong fluid also looks good and say I may have some kind of drive-line slip cause by ABS system. Okay, so I put it all back together and now for the suspension pump I did all the following I check for codes again got nothing. so I automatically just changed out the air compressor, cleaned the ground under driver side seat for ABS pump also ground for air pump. changed both ABS hubs and sensors in front, changed to front electronic shocks and rear air shocks, and left front CV joint. After all that I hot wire the pump to see if air pump works and it does, so I check all fuses and replaced gray suspension relay outside fuse box didn't work. I turned the key on checked the relay for power and red power wire from fuse box it has 13.91 volts the other red wire going to i guess pump it has fluctuating numbers Ald. .005-.071 the brown wire had .008 steady and the blue wire had fluctuating numbers approximately. .005- .071. okay, so with no power coming out the other side of the relay I bought another relay plug wired it up tested it I got the same readings and still nothing works differential or air pump. please tell me what's wrong.
Dec 9, 2012 at 3:15 AM
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ASEMASTER6371
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can you activate the air suspension pump with your scan tool?? you may have a bad controller for the suspension.

did you check the front drive shaft u joints???

Roy

Dec 9, 2012 at 3:40 AM
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RODNEYNME
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Nope can't activate with innova 3160 also yes I checked all u-joint and no problem there either.
Dec 9, 2012 at 3:52 AM
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ASEMASTER6371
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you have to see if it is a control issue for the suspension. can you check for codes??

Are all the mountings for the front differential working and tight??

Roy
Dec 9, 2012 at 3:57 AM
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RODNEYNME
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Yes, it's a control issue what controls it what part activates it when ignition turns on . Yes differential is tight mounts are okay.
Dec 9, 2012 at 4:16 AM
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RODNEYNME
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With me checking the suspension relay plug outside the fuse box power comes out one side brown and blue wire that comes from PCM numbers i got doesn't that has something to do with the PCM not sending a a signal or maybe the EBCM relay not working or what about the steering wheel position sensor .
Dec 9, 2012 at 4:31 AM
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ASEMASTER6371
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PCM does not control air suspension. there is 12 volts constant power to the pump and the ground is controlled by the controller..

steering wheel position sensor is a load sensor.

Roy
Dec 9, 2012 at 4:35 AM
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RODNEYNME
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So what's the controller I replace that?
Dec 9, 2012 at 5:05 AM
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RODNEYNME
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It's ESC module I will just replace that. thanks for your help.
Dec 9, 2012 at 5:31 AM
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CADIEMAN
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There is a sensor on the body it has an arm on it by the rear axle. This makes a car ride higher or lower.the linkage goes from the arm to the axle. You adjust it by that bolt on the arm. This controls the rear of the car.
Jan 14, 2013 at 6:36 AM