2008 escalade electronic suspension control module

My problem is that my compressor is not running I have a good power and ground to the electronic suspension control module and also have 5 volt ref on pin 2-6 just checked them to see if the electronic suspension control module was responding but when I check pin #8 alc excust solenoid control I have nothing here is a wire diagram I guess what I'm wondering is pin #8 controlled by the electronic suspension control module ? I have a code c0660 level control exhaust valve circuit short to ground or open (symptom 6). Any help would be appreciated

So, with the engine running, you have 0V at pin #8 of the suspension control module?

To answer your question, yes, pin #8 is controlled directly by the ESCM. It uses a ground side switched driver to energize the exhaust solenoid in the compressor assembly.

If you did find 0V at pin #8, then I'd say the code description is accurate. Short to ground on the white wire, open in the white wire, open in the solenoid, or missing power feed to the solenoid. Exhaust solenoid failure is the prime suspect, IMO. BUT, we're not parts changers. :lol:

We'll need a few more voltage checks at the compressor assembly to make a call. KOEO, voltage at pin B and C, backprobed at the compressor. If you find 0V on pin C and 12V on pin B, disconnect the compressor and install a test light from B+ to pin C. If the bulb does not light, the solenoid is open.

You might be able to find the solenoid separately somewhere? But last time I knew, it was only available as part of the compressor assembly.

No I didn't check with it running just with key on I never thought of it running but your right it'll check it running. Thank you

Also do you know if I have to change the ESCM will it need reprogrammed

bizz2222 wrote:

No I didn't check with it running just with key on I never thought of it running but your right it'll check it running. Thank you

Key on should be fine, too! Did you find the solenoid electrically open? :huh:

I can't say I've ever seen an ESCM fail. But to answer your question, yes, the ESCM will require programming and calibration if replaced.

Tyler, I had 12 v at pin b but nothing on the pin c the white wire and the air ride motor and whole unit are new well aftermarket the whole problem started when motor rotted away and froze up and it melted the plug and the ALC relay its located under the fuse box so i replaced all that to and i have got 2 different ESCM used from salvage yard but never reprogrammed either 1 of them so thats probably my problem what threw me off was i had a good ground and power to the ESCM i had the 5 volt ref just nothing on the white wire ALC EXH solenoid coming from the ESCM just seamed like i had everything but power to the white wire so wasn't sure it had to be programed. Thanks again Tyler for the help

bizz2222 wrote:

Tyler, I had 12 v at pin b but nothing on the pin c the white wire

Right, I got that. But did you determine if the solenoid was open, the wire was open, or if there's a short to ground?

If I'm reading you right, you've tried two different used ESCM's. Programming is important, sure. But I'm inclined to think both of the used ESCM's are telling you the truth about that solenoid circuit. Especially given the voltage readings you took.

Try this for me. Key off, disconnect the ESCM and measure voltage on pin #8. If it's zero, the problem is NOT in the ESCM.

Tyler I haven't got back to the escalade yet probably a day next week I will let you know I will try what you said and get back to you. Thanks again

If you have power on one side of solenoid but not the other and fuses are good then load test the wire going to the solenoid from fuse box. The white wire is the control (switched to ground by escm). So with it unplugged you shouldn't have voltage on it. With it plugged in it should have voltage unless it's shorted to ground. So to see if that's the case hook test light to battery positive touch white wires pin and see if it lights. If nothing when not commanded then try back probing both wires in place of solinoid and see if it lights when commanded. If not then it's the module. If it does light then the solenoid is bad on the used parts.

Thank you I will try that