LS1b PCM, A/C Type

[Lextech]

Hey Guys. In Tunercat > Constants > Type of A/C on Vehicle. Does anyone know how many types there are, and what does each type correspond to? Pin C2-17 is the A/C request into the PCM from the HVAC controller and C2-18 is the output for A/C Compressor Clutch Relay Supply Voltage. I am thinking this would be good to know for retrofit and custom applications.

Jeff

[T-Rex]

Here's some of them.......

[Lextech]

Nice! Thank You.

Jeff

[EagleMark]

Looking at OS 12212156 in EFI Live there is a Type of Fan Fitted and this:

Select the type of cooling fans fitted to the vehicle, the PCM supports the following types -
1. Series Parallel Fans - Where both Fan Outputs (1 & 2) are used to control two fans.
2. Auxiliary Fan - Where just Fan1 output is used, generally these vehicles will also have a mechanical clutch fan.
3. No Fans - Only a mechanical clutch fan is fitted
4. EV Fan - Used on later model vehicles, the fan speed is variable by means of a PWM output.

Only the following values may be entered into this table:
- Series Parallel Fans
- Auxiliary Fan
- No Fans

Which is differant then Auto Reciculation or Fan #2 control.

The PCM has a few dual purpose outputs.
The A/C auto recirculation output is also used for cooling fan #2 control.
This option changes the output for either A/C auto recirculation control or as cooling fan #2.

Only the following values may be entered into this table:
- Fan #2 Control
- Auto Recirculation

[Lextech]

Thanks Mark,
I'm not having any troubles understanding or implementing any of the cooling fan options. I am mostly curious about the "A/C On" command input to the PCM for the different A/C Types. There appears to be 3 different types of A/C. I am wondering, do the different types take a different input to the PCM for the On command (12Volts or Neg trigger, Momentary or Constant input)? Since the input/request pin is C1-17, I'm assuming none of the types are Serial input.

Jeff

[Caleditor]

Here's some of them.......

Hey that sheet is too old

[Caleditor]

Thanks Mark,
I'm not having any troubles understanding or implementing any of the cooling fan options. I am mostly curious about the "A/C On" command input to the PCM for the different A/C Types. There appears to be 3 different types of A/C. I am wondering, do the different types take a different input to the PCM for the On command (12Volts or Neg trigger, Momentary or Constant input)? Since the input/request pin is C1-17, I'm assuming none of the types are Serial input.

Jeff
Jeff I have tuned so many AC parameters and fan parameters for swap jobs I have lost track of all of them. The PCM must have the correct service number or Tom and I can convert a non DBC PCM into a DBC PCM. The fan tune gets kind of funny. You must know a lot of details to get it correct.

http://i1106.photobucket.com/albums/h361/PCMCalibrator/PCM%20and%20ECM%20Types/DBCupdate.jpg (http://s1106.photobucket.com/user/PCMCalibrator/media/PCM%20and%20ECM%20Types/DBCupdate.jpg.html)

Most PCM Calibration has 5 Fan options
Mechanical Fan
Electro Mechanical Fan like in the T-Blazer, but an option on 2003+ regular trucks
Single Electric Fan
Dual Electric Fans
Auxiliary Fan

The Calibrations have 2 AC Compressor Types
Fixed Displacements that need to be cycled on and off to prevent freeze-up
Variable Displacement that runs all of the time and even at WOT. These use a wobble plate.

The AC systems have several types of AC switches and sensor configurations. The calibration need to be correctly configured to the switch and sensor configuration. The fan settings need to be correctly configured to the switch and sensor configuration options.

Switches and Sensors
Low Pressure Switch
High Pressure Sensor -- 3 wire
High Pressure Switch -- mounted in the back of the AC compressor
High Pressure Switch -- Mounted on the AC Comp Discharge line
AC Auto Recirc Switch