@bronxteck might see how it acts till next weekend but ill give those a go when I can, pretty confident no mice, havent seen any evidence

1. AS - clicking sounds are probably the airbag solenoids operating agreed but its random and sporadic like a short , also did notice it also does it with the truck running if a door is open, compressor isnt running; pulled the compressor in and out a few times and rechecked that ground also when I did the rest a couple days ago; "It also shouldn't operate with the engine idle." guessing you mean not running, I think it will sometimes purge to level after its turned off that is not this tho. No issues with wipers, work normally.

2. Keyless - DDM works as expected lock and unlocks all doors; No aftermarket keyless or alarm. I need to test if I get door notifications on the DIC if each door is open, didnt realize it only pops up in drive. This also made me think of something else. with it not unlocking reliably I did unlock the driver door with a key and the alarm immediately went off which shouldnt happen using the key so going to look around and see if I can find anything on that.

3 Battery - disconnected it when swapping plugs, wires, and coil from 5 to 7 after putting it all back together I let it idle for about 10 mins with no codes, did a crankshaft position sensor relearn and drove it around without an codes or obvious misfires, it would chug under low rpm under load.



Does rocking the vehicle with the tailgate open cause clicking sounds? Never noticed it, next time it acts up ill give it a shot
What happens when the tire inflator switch is activated with the engine off. Nothing

 

With so many issues, for the moment let's focus on the AS.

The random and sporadic clicking is curious suggesting the following possibilities:-

1. Faulty ECU
   There's at least 2 versions of module, one for single compressors and one for the later dual compressors units, not sure if a dual ECU works in a single (possibly) A faulty ECU with faulty comms, prompted taking a deep interest in AS-Units, after un-potting the defective ECU module the problem was a bad PCB track, this was repaired and the module now works.
   
   A faulty AS-ECU can affect serial comms around the vehicle, try unplugging the 16-Way connector to the AS-Unit and see if the door locking issues goes away.
   
2. Intermittent connection or faulty wiring
   The pins in the 16-Way connector linking the main harness to the AS-Unit can become corroded and can cause the wires to rot (copper inner cores turn black) It's worth giving the connector a good flex and waggling the wires to see if this makes the fault come and go. Inspect the connectors male/female pins, any signs of corrosion may indicate a problem. One AS-Unit started playing up causing a MIL code related to the AS relay, it turned out to be a corroded pin and rotted connecting wire.
   
   The ECU module plugs into a IP 24-Pin connector, it's worth inspecting and cleaning with some IPA based residue-free contact cleaner.
   

The Tech2 Air Suspension "Data Display" provides a wide range of useful information, monitoring these whilst the clicking is happening may provide a clue.

1. Ignition On/Off status
2. Ignition 3 voltage level
3. Battery Voltage Level
4. Ride-Height Status
5. ERH Switch On/Off Status
6. ERH Lamp Command On/Off Status
7. Inflator Switch Lamp On/Off Status
8. Inflator Switch On/Off Status
9. Compressor Relay On/Off Status
10. ALC Exhaust Solenoid Active/Inactive Status
11. Right Isolation Valve Active/Inactive Status
12. Left Isolation Valve Active/Inactive Status
13. Total Valve Current in mA
14. Right Height Sensor voltage
15. Left Height Sensor voltage
16. Height Sensor Current in mA
17. Height Sensor Supply Status On/Off
18. Rear Levelling Pressure in PSI
19. Rear Levelling Pressure voltage
20. Compressor 1 Temperature Status
21. Compressor 2 Temperature Status

 

I ended up replacing the battery, plugs, wires, MAF sensor, and fuel pressure regulator. I also disconnected the battery for awhile and did a crankshaft position sensor relearn and it seems to at least be running normal again. No clue if that fixed the initial complaint but seems to have fixed the miss fires.


So going back to the odd electrical issues with the air suspension and remote unlocking. I tried to unlock it with the fob recently and it wouldnt unlock so I used the key in the driver door which ended up setting the alarm off.

if locked with the fob does unlocking with a key in the driver door disable the alarm or should it? under what conditions does the keyfob not unlock the doors?

I tried jiggling the wires at the AS when I noticed it clicking and it didnt seem to effect anything or cause it to click, I think its getting a bad signal from something else.

 

"I think its getting a bad signal from something else"

Below is a wiring diagram for the AS unit showing all connections in and out' you can see the AS Unit is self-contained with only 3 "signals" as you refer to them,

1. Class 2 Serial - this is the only true signal, it provides comms between BCM and AS-ECU, the ECU controls the solenoids so can't be that
2. IGN3 - This has two functions within the ECU,
   • used by the ECU to detect the ignition is "ON"
   • provides power to the Inflator Switch lamp and associated ECU control electronics
3. BATT+ - the main +12V feed, powers the ECU, solenoids, the AS cannot function without it.

It's unlikely and of these these would cause the "clicking" sounds.

Probably the best course of action is to identify the source of the sound :

1. Left Inlet valve
2. Right inlet valve
3. Exhaust valve
4. Compressor

these are the only electro-mechanical devices on the AS-Unit and so the most likely sound sources.