HOW TO: Convert CJ2 automatic -> CJ3 manual climate controls

[mikez71]

1. Remove radio trim. (plastic prybar)
2. Remove switchbank under hvac controls (7mm socket)
3. Remove HVAC module. (7mm socket)
4. Re-pin/de-pin ~11 wires shown below (pin removal tool or fine pick)
5. Splice illumination wire (YE) from J1-4 switchbank plug to J2-1 HVAC module. (2' of wire and some splice connectors)


CJ3 Manual HVAC module
-----------------------------
'07-'09 have different climate control part numbers than '10-'14. MAKE SURE you get the RIGHT ONE!!!
Earlier models have an AC low pressure switch connected. Later models have the evap temp sensor.

J2 PLUG
----------
Manual control J2 plug is blue. Original automatic J2 plug is black.
It will not plug in directly, but looks like it should with a little modification to the lower alignment slots.

I de-pinned the wires, intending to re-pin them to the new connector. Reversible if problems.
The '07 plug I purchased has different pins than my '12 model.
So I ran the new J2 pigtail wires through the original unplugged pin receptacles, then heatshrinked around each wire/receptacle.
(I have since acquired a 2013 J2 blue connector which will accept the original pins from my 2012)

To remove the pins, first remove the retainer (J1 plug, pin style shown, enclosure retainer on older connectors)

Insert a fine pointy tool pointing to the bottom of the "T" slot, then pry upwards pointing to the top of the T to release the plastic tab holding pins in.
Pull wire while holding tool. (ebay pin removal tool shown)

WIRING CHANGES
---------------------
auto CJ2 (BLACK J2) -> manual CJ3 (BLUE J2)

J1-18 (PK) -> J1-8 (PAS AR TMP SW SIG)
J1-19 (GY) -> J1-18 (RR MOD MOT SIG)

J2-1 (RD/WH) -> J2-4 (HVAC BATT)
J2-8 (BK/WH) -> J2-3 (GROUND ZONE 18)
J2-9 (OG) -> J2-2 (HVAC MAN RUN)
J2-15 (BK) -> J2-10 (BKLT GND)
J2-10 (WH) -> J2-8 (RR DEFOG RLY CONT PWR)
J2-4 (L-GN/BK) -> J2-9 (OUTSIDE AIR TEMP)
J2-16 (D-GN) -> J2-12 (TEMP SENS COM LO REF)

J4-6 (GY/BK) -> J4-5 (LOW REF)

Wire below needs to be added for backlighting. Auto display has it's own brightness control that get's network data for dimmer level.
I spliced from switchbank wiring, also yellow wire.

J1-4 Switchbank plug (YE) ---SPLICE--> J2-1 (HVAC LED BKLT)
J1-3 / J1-6 can also be used if Cadillac switchbank.
-------------------------------------------------------------------------------------------
The wire below is UNUSED in the manual controls, *but* the module does have a pin in that location.
***UNPLUG*** this wire just in case!

--J3-3 (PU) RECIRC DR PSN SIG ---> UNPLUG
-------------------------------------------------------------------------------------------

Stock wiring from a 2013 manual CJ3, some wires are for the rear roof mount dial controls, which are unused on my truck.

'10 thru '14 CJ3 manual models, the EVAP TEMP SENSOR ground is *SUPPOSED* to be connected to J3-19.
In the automatic controls, the evap ground was spliced with other grounds connected to J2-16.
(X2-16 in the charm.li diagrams for the automatic controls)
I left the original connection and seem to get a proper reading on the Tech2. I guess both ground pins are connected internally.
------------------------------------------------------------------------------------------
'07 thru '09 diagrams show an AC LOW PRESSURE SWITCH, that is wired to J2-6 (D-BU)
Other side of switch is grounded.
------------------------------------------------------------------------------------------
Unpopulated pins shown. J4-1 & J4-9 aren't visible, but they are vacant.
Camera too close. The circles are vacant, and the pins that look like they maybe in the same spot, are actually 1 or 2 pins over.

A big "THANK YOU!" to J91z and everyone who helped out!

 

[89Suburban]

Any pics? Diagrams? Appreciate you sharing.

 

[mikez71]

The factory '08 HVAC diagrams are about 8 pages each, with extra temp sensors and different pinouts being the main differences.
Mostly need to compare both Page 1's (353, 364), and manual Page 6 (369) with auto Page 7 (359).

https://www.gmupfitter.com/wp-content/uploads/2021/05/2008_LD_ElectricalPickupsChassisCabs.pdf

UPDATE: Prefer to use this site for updated wiring diagrams..

Free Service Manuals for Chevrolet vehicles | Operation CHARM

Detailed repair/service/workshop manuals for many Chevrolet vehicles, including electrical diagrams, recommended bolt torques, and estimated labor times.

charm.li

evap temp sensor auto CJ2 wiring shown below, ultimately I left this alone and still get an evap temp reading.

#15 is where the J206 splice should be...

 

[mikez71]

https://i.ebayimg.com/images/g/D7oAAOSwj-dlxhp0/s-l1600.jpg

Link showing most of the wire colors and locations. It seems to show the wires as listed in the '08 diagrams..

 

[j91z28d1]

what diagrams are you looking for? I can look up. what my software shows.

 

[mikez71]

Looking for the 2012 manual HVAC. Think I found a free site here someone posted before....

HVAC - Manual — 2012 Chevrolet Tahoe 4WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2012 Chevrolet Tahoe 4WD V8-5.3L.

charm.li

I feel like the wiring should is correct, these are the codes I'm getting..


B0433 61
- Temperature Control 3 Circuit Actuator Out of Range / Stuck

B3782 61
- Air Flow Control 10 Circuit Actuator Out of Range / Stuck

Rear roof vents stuck off the last time I went for a drive, when previously they were stuck on.
I was getting about ~5V on J1-8 and J1-18, but still unable to control rear temp or rear mode.

------------------------------------------------------------------------------

Tech2 showed commanded door positions properly, actual position varied very little.
Showed commanded aux temp. +0 to +12 equaled 0 to 255 'counts'. But temperature did not change.
Changing the aux mode would command 0, 115?, or 255 and seemed to work at turning off roof vents in face position.
But actual 'sensed' door position changed very little.

Have done actuator relearn procedure a few times.

J4-2 (5V REF for both rear aux actuators). J4-2 did not change positions/purpose.
My measurement would quickly drop in voltage. Would not show 5V using chassis ground

J4-5 is LO REF GND. Not sure how to test these?

 

[j91z28d1]

this is a 2012 5.3 manual hvac. hopefully the quality is good enough to read.

 

[mikez71]

this is a 2012 5.3 manual hvac. hopefully the quality is good enough to read.

quality is great! Thank you.

Looking at the auxillary mode and temp. Wiring seems correct, not sure what I'm missing. Will take more readings tomorrow!

 

[j91z28d1]

cool. left me know if you want me to look anything else up.


I ordered one of those OBDx dongles that might be able to let you flash the truck to setup it up for manual? unless the tech 2 will do that.

 

[mikez71]

Don't think Tech2 can program, keep me updated on the OBDx device!

Checked my 5V REF (J4-2) to LO REF GND (J4-5) reading 4.8V with key on engine off.

I'm just trying to understand how to test these actuators. Starting to wonder if I could have damaged the module from plugging it in before I had repinned anything.

 

[j91z28d1]

I don't know on these trucks. but on a c6 it can make setup changes, like if you have active suspension or not. some guys have added and used the tech 2 to go into setup and configure the options.

maybe something like that?

 

[mikez71]

Couldn't find any special functions on the Tech2 other than afterblow and recalibration and some temp display option which doesn't work and says I selected the wrong vehicle.

I notice the automatic HVAC can either be BEHR *or* DELPHI, the actuators are outiside of box on the BEHR, inside of box for DELPHI. The manual HVAC has *only!* DELPHI, mine were/are BEHR. The actuators are located on the OPPOSITE side! If you do not have the actuators located on the inside, you may need a donor rear box..

BUT I wonder if the '08 wiring manual showing the var/src and ref/rtn circuits flipped would work??. They may have been planning for a behr manual setup, but actual production omitted behr..

 

[j91z28d1]

I can look up the 08 manual hvac if you want to look.

I hope it didn't fry anything, but if there's a pwm output or 5v output that got 12v put into it. that would toast a fett ******.

 

[mikez71]

Yep, those wires weren't really changed, shouldn't have fried anything near as I can tell!?

Ordered a couple actuators and will check the actuator wiring when puttin them in..

---UPDATE---

removed ducts to watch actuator doors.
doing recalibration, everything moved smoothly, full range of motion.

watching tech2 info, when changing rear mode, actual was inverted from commanded.
Example 0 commanded would be 255 actual, 255 commanded was 0 actual position.

Hoping this is as simple as swapping polarity on a couple wires. I have old actuators out to do some testing.
I really wonder if this has to do with the wiring diagram difference between Behr/Delphi in the '08 factory diagrams.

 

[j91z28d1]

so looking at the modules in my car today on the sps software. I did see some how the option to program or configure/setup. I don't remember exactly the wording. I will have it in my yukon in a few days or so. I'll try too check what options it gives.

 

[mikez71]

so looking at the modules in my car today on the sps software. I did see some how the option to program or configure/setup. I don't remember exactly the wording. I will have it in my yukon in a few days or so. I'll try too check what options it gives.

awesome! Thank you!

I haven't messed with the wiring anymore figuring it should be correct. (Other than that one wiring diagram discrepancy...)
According to the free repair website, the manual HVAC's should all be using the DELPHI ductwork, but if wiring and actuators are the same, I don't see why it doesn't work.
The only thing I can think of, is if the Delphi ducts have a different range of motion than the Behr.
I do notice some vehicles have the manual roof mounted climate controls. Probably overthinking things at this point..

Perhaps it is a programming thing. The rear temp adjustment being +0 to +12 seems odd to me..
*IF* programming, I would guess it's the integrated rear seat audio module..
Unless the BCM is a go between. Say the rear controls send signals that BCM reads, before spitting out a new signal to the main HVAC module..

 

[j91z28d1]

I feel like there's gotta be a configure or programming of some sort to make this work.

I have been to busy to get to my yukon. but a few of the modules I updated on my car had the option to program or configure. and my c6 will go into configure with the tech 2 on the bcm. like I can select the mag ride or not from it.

 

[mikez71]

No options i could configure in the Tech2 for rear audio..Will check bcm next time but im pretty sure I looked before.

I might try disconnecting Rear controls to test, like a ppv. Though ultimately I will want the rear controls installed.

Certainly must work somehow..

tried moving old actuators with a 9v, no dice. Will power the motor directly, but doesnt budge when powering pins 5(+) and 7(-), or 5 and 6+7.

 

[j91z28d1]

No options i could configure in the Tech2 for rear audio..Will check bcm next time but im pretty sure I looked before.

I might try disconnecting Rear controls to test, like a ppv. Though ultimately I will want the rear controls installed.

Certainly must work somehow..

tried moving old actuators with a 9v, no dice. Will power the motor directly, but doesnt budge when powering pins 5(+) and 7(-), or 5 and 6+7.

I seem to remember there's a bench test in the manual where you can test the motors. I'll have to look that up again. I got a fault code for one of mine, it never lit a light and seems to work fine, but when I happened to scan the whole truck it came up with a temp actuator code, even thou the temp control works. so I was reading about them.

 

[mikez71]

Maybe you had an old stored code? I will try again with 12v before too long..