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2016 2500 LML Duramax LT Manual AC Upgrade (C67) to Automatic (CJ2)

ReelNice

By ReelNice
in Modifications & Accessories

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ReelNice New Member

ReelNice

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Inspired by Darth's post here:

I am going to try and retrofit my 2016 2500 LT Silverado with auto air.  Using Rock Auto for parts and The Body Builders service manual I came up with these notes and some questions for anyone that has done this:

Presumptions:

X1 and X4 connectors are absent and we need sun sensor, upper left temp sensor, and lower left temp sensor.

 

According to Rock Auto:

  There are two versions of HVAC for the 2016 Silverado 2500.  The C67 (manual) and CJ2 (auto).

 

Control Module

The part number for the manual Control module is 1574848 and it's lacking the J1 connector in the picture.  

The automatic version is 1574531 and it has all 4 connectors (J1-J4) pinned out.

 

Instrument Panel

There are several versions of the Instrument Panel for C67, but only one version of the CJ2 which is 1574881

 

Air Duct Temp Sensor(s)

The CJ2 instrument panel air duct temp sensor, front. is 1551332.  Should need two of these upper and lower I am guessing.  Wire color is blue and black/yellow
Pins are 
Left Upper BU to X3-1, Bk/YE to ground X3-9.  
Left Lower X4-11 (shows Green...but must be Blue), BK/YE to ground X3-9

The wiring diagrams on 246 and 254 show the sensors are there on both versions, but the diagram on Page 479 showing the sensor location labels them as CJ2. 

Considering they are on connector X4 which doesn't exist...I imagine that's a typo in the diagram.

 

 

Sun Sensor
There are two versions of the sun sensor.  C67 is 13525289 and CJ2 13525291.  .  They look identical but CJ2 version definitely has more pins.

Sun Sensor wiring shows 3 new wires needed to the control module X1 Connector
X1-4 BU/WH to Pin 3 of sensor
X1-14 YE/VT to Pin 4 of sensor
X1-13 YE/VT to Pin 4 of Sensor
X1-20 GY to Pin 2 of Sensor

 

Other Notes:

X4 connector also has a new actuator for M6L air temperature door actuator left in CJ2 version.  Presumably for Sync...since this is located under the dash (is it?), I am skipping this.

The X4 Connector on page 947 is showing (CJ2) by it's name, X1 on page 944 is not showing (CJ2) and has some wires on  18 & 19 (Lower Air Temperature Sensor).  Can't find anything on these.

 

My questions before I get started:

The X1 Connector on Page 944 shows X1-18&19 pins as Upper Air and Lower temp sensor.  WTF are these and do I have an X1 connector?  Sure seems like it's there in all diagrams.

 

Does the wiring harness plug already have the extra pins needed for the Sun Sensor?  If so, where do the wires stop? If not, how did you add them?

 

Are there holes there for the temp sensors?   How do you get access to them?

 


 

 

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