A/C pressure pegged?

[07_zq8]

Ive been trying to set up my wideband through the 0-5v ECM input from the high pres. side a/c sensor. I have read about dozens of people doing this on other GM vehicles. I added A/C pressure to my table just to watch the readings, and it is always stuck at 184.92psi whether the a/c is cycling or not. The value never changes, which means if I did happen to run my wideband analog output thru this pin it would be worthless. Why has this worked for so many others, but VCM Scanner can't read/interpret the A/C pressure voltage coming through? I have even put a voltmeter to the output wire on the sensor and it varies from .88v up to 2.0v when the compressor cycles, but none of this is seen or recognized through the scanner when its happening... Seems like there is a bug in the software thats hanging up the reading. what is the most current beta?

[HawkZ28]

I didn't have any problems with mine, but I have a P12 and it's been a while since I've messed with it. Did you notify support?

[07_zq8]

I also have a p12 in my 2007. I am currently in a back and forth email correspondance trying to get it figure out. did you use your AC to log wideband? cause thats what I am wanting to do :-) maybe got a config you could should me to try if yours was an 07?

[HawkZ28]

mine is a 2005 P12. mine is working fine and showing bolts- I am also running the latest beta.. are you sure that your not logging the pressure in psi- there are 2 choices to aclog ac pressure. Posting from my phone so sorry to be short.

[07_zq8]

the items boxed in red show the different PID's i tried, all reference the a/c High side sensor, and all pegged/stuck at those values

[planethax]

What vehicle are you working with?

[HawkZ28]

You are logging the wrong pid. Log ac volts not ac psi. That's why your wbo2 pid is all jacked up too.

[cobaltssoverbooster]

3,000 v lol reminds me of working on old v12 Benz. Lean over the front grill and just happen to find a bad ign wire with ur hand u were the fortune soul of the day to experience the weenie zapper.... In through hand & out your no no square at the metal grill lol
I love old stuff, now everything is plastic and breaks.

Sorry off subject

[07_zq8]

If you noticed at the top of the table you will see a/c pressure logged in volts, and the WB02 is just a function PID that uses the Sensor reference IF the scanner were working correctly to see my 0-5v a/c sensor output. I have tried using the PID to get it to read and the sensor itself, and both are displayed but frozen at max values. I can send you my config/log to show you if you really want. the pressure/volts never changes when I log/scan, its always stuck at these values...

[HawkZ28]

My bad-posting from my phone so i missed that upper corner entirely.

Do the values still freeze with your wbo2 completely disco'd or is it already disco'd in the screenie?

[HawkZ28]

Btw, contact support for the latest beta.

[Chris@HPTuners]

try deleting everything from the table display (right click -> clear table) and just log RPM and the two AC PIDs, maybe something funky going on with the config.

[5_Liter_Eater]

Looks like a $hit ton of PIDs being logged. I've seen very funky things happen when the number of bytes is exceeded. Like IAT, water temp, etc. pegging or not reading.

[07_zq8]

My bad-posting from my phone so i missed that upper corner entirely.

Do the values still freeze with your wbo2 completely disco'd or is it already disco'd in the screenie?

wideband isnt even hooked up through the A/C sensor, just the a/c pressure sensor itself. I thought I had the latest beta but I will email about that too, I am waiting on them to get back about this issue, for almost 2 weeks now.

[HawkZ28]

try deleting everything from the table display (right click -> clear table) and just log RPM and the two AC PIDs, maybe something funky going on with the config.

Looks like a $hit ton of PIDs being logged. I've seen very funky things happen when the number of bytes is exceeded. Like IAT, water temp, etc. pegging or not reading.

What they said- I've found too, that if you are logging a ton of PID's, it slows the polling rate (correct terminology?) down considerably too. I thought I had a lazy O2 until I deleted the un-needed PID's from my config and found I was just trying to log waaay too much info simultaneously.

wideband isnt even hooked up through the A/C sensor, just the a/c pressure sensor itself. I thought I had the latest beta but I will email about that too, I am waiting on them to get back about this issue, for almost 2 weeks now.

Try Chris's suggestion- see what it does and report back. Hang in there- Chris is like the Navy Seals, Chuck Norris, and Bob Barker all rolled into 1 with HPT.

[07_zq8]

Ill give this a try tomorrow, thanks guys.

[07_zq8]

logging just the a/c PID and sensor didnt change, its still pegged at max value. sure would be helpful in tuning the VE tables with this blower on...

[HawkZ28]

I'm stumped. You're ac works fine otherwise? I'm beginning to suspect something mechanical like the oem wiring.

Did support add the link to download the latest beta to your customer page?

[07_zq8]

I just emailed them about the latest beta, even though Im pretty sure I do have it already... this is tough :-)

[07_zq8]

I ended up installing the latest beta on a different laptop that had windows 7 instead of my crappy vista and it actually showed an A/C Volts PID [PID.7101] next to the A/C pressure PID [PID.7100]. I have always had the pressure PID but the volts one is new, and it works, so I have been logging WB AFR and tuning finally!! thanks for all the help guys!