Rear A/C oddities

[George B]

So that's the only considerable difference other than a wider range of vehicles- convenience of an all-in-one package? I have a dedicated laptop for HPT. It'd make good sense for me to add the MDI 2 functionality to it. Between that, the HPT scanner and my Autel recording live data of any selected PID(s), I should be covered whether I'm parked and activating modules or datalogging while moving for drivability diagnostics.

I'm not trying to skirt around getting a Tech 2 as much as I'm trying to use what I already have and gain what I don't for just ~$200. I could get some velcro straps to be fancy and hang the Autel on the steering wheel like the Tech 2.

I believe @Joseph Garcia has the lowdown on this.

 

[Geotrash]

So that's the only considerable difference other than a wider range of vehicles- convenience of an all-in-one package? I have a dedicated laptop for HPT. It'd make good sense for me to add the MDI 2 functionality to it. Between that, the HPT scanner and my Autel recording live data of any selected PID(s), I should be covered whether I'm parked and activating modules or datalogging while moving for drivability diagnostics.

I'm not trying to skirt around getting a Tech 2 as much as I'm trying to use what I already have and gain what I don't for just ~$200. I could get some velcro straps to be fancy and hang the Autel on the steering wheel like the Tech 2.

I'm personally interested in following along on your journey if you decide to go this route. I also have a laptop I could dedicate to this purpose if it proves viable.

 

[Joseph Garcia]

I believe @Joseph Garcia has the lowdown on this.

I really don't have much to add to this thread. I have only 1 truck, and my Tech 2 works very well for diagnostic, testing, and programming. I successfully analyzed my Electronic Suspension Module, height sensors, and shock dampers together for extended periods in real time using the Tech 2 alone, so I have no use for a PC, other then being a connection and pass thru device when I program control modules with the Tech 2.

 

[George B]

I really don't have much to add to this thread. I have only 1 truck, and my Tech 2 works very well for diagnostic, testing, and programming. I successfully analyzed my Electronic Suspension Module, height sensors, and shock dampers together for extended periods in real time using the Tech 2 alone, so I have no use for a PC, other then being a connection and pass thru device when I program control modules with the Tech 2.

I thought you had info on using SPS. Don’t you need a subscription for that?
I have the impression you need a subscription to use the MDI for diagnostics but I was not sure. I thought you knew more about that.

 

[Joseph Garcia]

I thought you had info on using SPS. Don’t you need a subscription for that?
I have the impression you need a subscription to use the MDI for diagnostics but I was not sure. I thought you knew more about that.

To do any programming, you do have to connect to GM Techline Connect to obtain the programming data bits to transfer to the truck's affected control module. You do need a subscription to GM to receive any programming data bits. I have a post in this Forum describing the process for navigating the GM Techline Connect screens to perform programming.

 

[George B]

To do any programming, you do have to connect to GM Techline Connect to obtain the programming data bits to transfer to the truck's affected control module. You do need a subscription to GM to receive any programming data bits. I have a post in this Forum describing the process for navigating the GM Techline Connect screens to perform programming.

Thanks and sorry to tag you incorrectly.

 

[iamdub]

Yesterday, after a long run time with the front and rear ACs on, I checked the lines to the rear evaporator again. Yup- they were ambient temps.

 

[gpracer1]

If your expansion valve is stuck closed then they will be ambient. Try smacking it around a little without damaging anything.

 

[mattbta]

That'll work, just check with ACDelco's TDS system to make sure the laptop is up to their standards in case you need to program.

Ironically, I recently used a 2010 Lenovo T510 with the latest Techline Connect to program my radio for the Lux conversion. That thing is old as balls and did fine. . Delco was very specific about the OS bits and Java version and I just went with their requirements there.

Also used my VCX Nano as a passthrough j2534 as the connection between vehicle and laptop.

 

[iamdub]

If your expansion valve is stuck closed then they will be ambient. Try smacking it around a little without damaging anything.

After an ~8-mile drive the other day with ice cold front A/C, I knocked on the aluminum block where the two A/C lines run through the rear floor with a hammer. I tried from a few different angles and got somewhat frisky with it. No change.

At this point, I'm thinking either that valve is really locked up or the line to the rear is totally blocked, maybe from a past injection of leak sealer. The only way for me to know is to open up the system and inspect everything. Y'all know it's an all-or-nothing thing, so I'm gonna leave that can of worms closed until winter,