E-fan controlling on 02 Chevy truck

[aaronr]

Yes the lines still ice-up on the Camaro system segment swap. Well let me know what you come up with. Maybe pin A is the issue and that why the compressor isn't cycling.

[Taz]

I should have confirmed earlier ... you are using an A/C Pressure Sensor for a 2002 Camaro (ACDelco # 15-5742, or the equivalent) correct ?

The sensor is new, and in proper working order correct ?


Regards,
Taz

[aaronr]

Yes it's a new sensor from 02 camaro. I' not sure what part # is off hand. A pin sensor is tied to body ground not low reference. Low reference is what call a clean ground. I ran truck tune to work today the compressor cycle just need too. Funny part is I can see what sensor is doing but don't have any programming to do anything with it. Let me know what you come up with.

[Taz]

... A pin sensor is tied to body ground not low reference. Low reference is what call a clean ground ...

With Camaros, pin A of the A/C Pressure Sensor is connected to PCM C2 pin 57. With trucks, PCM C2 pin 57 is the IAT Low Reference. That's from a cursory look at the schematics ... more to it than just that probably.

Perhaps it is a setting in the tune itself ... post your tune when you get a chance.


Regards,
Taz

[aaronr]

I don't have a truck pin out. I was using express van pin out because that what i could get my hands on. I see the truck use C2-55 for low side switch signal and that how it cycles the compressor. The camero doesn't use these ports for anything. I not shore how the camaro gets it's info to cycle the compressor unless it's looking at the a/c pressure sensor and cycles that way. I really don't think it's in tune but here you go. If you can look at wire diagram again see if you see anything let me know.

[Taz]

... I don't have a truck pin out. I was using express van pin out because that what i could get my hands on ...

Difficult to sort this type of conversion issue out, without OEM quality manuals - for all of the vehicles / platforms involved. Well worth the cost in the long run.

... not sure how the camaro gets it's info to cycle the compressor unless it's looking at the a/c pressure sensor and cycles that way...

That's exactly how the Camaro A/C system works - A/C Pressure Sensor input.


I was just taking a little break ... back to work ...


Regards,
Taz

[aaronr]

Well let me know if you see anything that might help me out. I just order some OEM manuals. To see if I can figure this out. Did you see anything that stuck out to you in the tune?

[Taz]

OK ... took a look through the schematics to confirm a few things.

The A/C Pressure Sensor operates on a 5 volt current - generated by the PCM. It must ground through a PCM 5 volt ground / low reference circuit. With Camaros pin A of the A/C Pressure Sensor splices into the 5 volt ground circuit of the IAT sensor.

Your truck uses an integrated MAF / IAT sensor. It has a 5 pin connector - pins A & B are the IAT sensor, pins C to E are the MAF. The MAF operates on a 12 volt current (pin D) and simply grounds to the chassis (pin C). The IAT operates on a 5 volt current, and grounds back (pin A) through the PCM.

On your MAF / IAT connector plug there is a black wire on one end (pin A) and a yellow wire on the other end (pin E).

I would suggest splicing pin A of your A/C Pressure Sensor to pin A of the MAF / IAT plug (the same way as a Camaro was wired).


Regards,
Taz

[aaronr]

Well here is what happen. I fixed the wire like Taz suggest in the post above but the compressor still ins't cycling. The a/c pressure sensor is talking to the fans fine but the a/c pressure isn't taking to the the compressor for some reason. I guess this why nobody has done it. Taz did see anything in the tune?

[aaronr]

Taz,
Do you see any issue with splicing C2-18 into Dk GRN a/c compressor clutch wire? I just don't under witch pin the a/c sensor pressure sensor need to talk to get a/c cycle. All 02 pcm are the same beside the programming inside correct?

Yes i'm i bought real manuals from alldata website. still leaning how to read these and get around on there web site.

Thanks for the help.