yet another autoride issue.

[Chughart]

ok guys i have an issue with the autoride on my tahoe (02 tahoe lt) i have replaced the rear air shocks and the compressor (shocks were busted and had no rebound) and i thought the compressor was bad as it didnt turn on so i replaced it as well (shocks and compressor were sold together). and then the compressor still did not turn on. checked the relay i have 3 powers and one ground and when i ground one of the powers (lt blue wire on the relay) the compressor engages. i checked the connections at the suspension control module (ESCM) and i have my powers and grounds going into the control unit and with a scan tool (snap on scan tool) when trying to command the compressor on it doesnt turn on at all and the data list shows that the compressor is still off even though it has been commanded on. so given this i assumed (yup made an ass of my self) that the ESCM was bad and ordered a used (yikes) ESCM and installed it today and you guessed it, the compressor still can not be commanded on and doesnt come on unless directly powered.

i have printed the entire wiring schematic for the compressor/ESCM but i do not know what all the control unit wants to see to turn the compressor on. im assuming that the pcm has something to do with it as there is a VSS input from the pcm to the ESCM. and i also see that the electronic brake control module (EBCM) sends some sort of data to the ESCM but i dont know what it is looking for.

i also have the code c0265- EBCM relay circuit that comes on and i was curious if this would interfere with the compressor engagement but like i said i have no clue what all the ESCM is looking from fron the other control units. i have the inputs from the shock height sensors and i can watch them change by adding weight to the back but like i said im in search of what all the ESCM needs to see as i need this to work lol

thanks in advance guys!!

 

[wjburken]

ok guys i have an issue with the autoride on my tahoe (02 tahoe lt) i have replaced the rear air shocks and the compressor (shocks were busted and had no rebound) and i thought the compressor was bad as it didnt turn on so i replaced it as well (shocks and compressor were sold together). and then the compressor still did not turn on. checked the relay i have 3 powers and one ground and when i ground one of the powers (lt blue wire on the relay) the compressor engages. i checked the connections at the suspension control module (ESCM) and i have my powers and grounds going into the control unit and with a scan tool (snap on scan tool) when trying to command the compressor on it doesnt turn on at all and the data list shows that the compressor is still off even though it has been commanded on. so given this i assumed (yup made an ass of my self) that the ESCM was bad and ordered a used (yikes) ESCM and installed it today and you guessed it, the compressor still can not be commanded on and doesnt come on unless directly powered.

i have printed the entire wiring schematic for the compressor/ESCM but i do not know what all the control unit wants to see to turn the compressor on. im assuming that the pcm has something to do with it as there is a VSS input from the pcm to the ESCM. and i also see that the electronic brake control module (EBCM) sends some sort of data to the ESCM but i dont know what it is looking for.

i also have the code c0265- EBCM relay circuit that comes on and i was curious if this would interfere with the compressor engagement but like i said i have no clue what all the ESCM is looking from fron the other control units. i have the inputs from the shock height sensors and i can watch them change by adding weight to the back but like i said im in search of what all the ESCM needs to see as i need this to work lol

thanks in advance guys!!

Not familiar with the relay setup on that generation of vehicles, but have you tried a new relay?

 

[Chughart]

Not yet but from what I gathered is the ground control for the relay to engage and then in turn, turn the compressor on, comes from the suspension control module and it’s not getting that signal at all and if i ground that ground control wire the relay clicks and the compressor comes on so I would say the relay is good? but whatever controls it isn’t? and that’s the issue I’m having as this is my first Chevrolet, I don’t know much about them.

I will post pictures of the wiring diagram here shortly and maybe somebody can point out what I’m missing or what my values are supposed to be

 

[Chughart]

i know this is kind of old but i figured out my air suspension issue, the system thought it had 168 psi in it when it shouldnt exceed 160psi (had scan tool hooked up trying to test) i unplugged the pressure switch/sensor on the compressor and plugged it back in and the compressor engages and everything works.

but i now have a weird thing going on with my steering where it is extremely sensitive when turning i thought it might be my alignment so i did one (i work at a shop that has an alignment rack) and it didnt fix it. i then came across the EVO solenoid issue and am wondering if i can put the bypass kit on and remove the sensor/switch for the EVO and my air suspension still work as the suspension control module gets a signal from the EVO sensor/switch. im going to assume it will still work as i unplugged the EVO sensor connector and drove it thinking maybe it would tighten the steering up but it didnt do anything and the air suspension worked just fine.