rustyguns

EXCELLENT ARTICLE. ANYWAY TO MOVE THAT GOOGLE ADVERTISING SO IT IS NOT BLOCKING THE TYPE?

Xtreme4U2NV

Greetings.

I drive a 2006 Chevrolet Colorado Xtreme.

I unplugged my blue plug on the PCM, and noticed I do not have a wire in pin 55, so I took the plug apart, and added on to pin 55.

I then went in to hptuners, and did all the required work, but yielded no results.

I have installed a handful of LC-1's through the A/C circuit, but my truck is the first one that I am trying to get through the EGR way.

Also, a semi-side note, those hooking up to the A/C circuit, you can install it in such a way that you can turn the reading on and off with a toggle switch. That's what I do.

I take a single pole, double throw switch, put the A/C wire to the center pole on the switch, the A/C pressure censor on the left pole, and the LC-1 to the right pole. That way, when I want to log, I switch it to the LC-1 side, and when I am not logging, I switch it to the regular A/C side.

Anyways, the reason I was making this post was to ask, that if I installed mine the EGR way, followed every step, but aren't getting it to work, is it possible that my PCM doesn't do anything EGR related, in order for me to log it that way? I hope thats not the case, because it was a pain in the butt trying to get the new wire in the pin 55 spot on the blue pcm plug.

EDIT: I got a friend of mine who is a GM Tech at a dealership, send me the pin-outs for my PCM. Pin 55 says "not used", so do that mean I lose out with the EGR option of hooking it up?

Joe_G

Bill, thanks again for your help. Got my wideband working great yesterday!

5 Liter Eater

My pleaseure. Happy tuning.

FourG63 97GST

let me know if you find an answer, i'm in the same boat with no results yet

roysvett

which wire from the lm-1 do you hook to the ac pressure wire

5 Liter Eater

One of the analog outputs. Preferrably #2 as I think #1 is configured to emulate a narrow band by default. Make sure you configure the output and configure your HPT PID to match.

http://www.innovatemotorsports.com/s...LM1_Manual.pdf

Joe_G

Bill I'm having fits too on this. In my PID I have to add 13.6 to get 14.7 cruise to be more or less equal on HP Tuners and the XD16 in the car. But at WOT the XD shows 12.3 and the HP tuners is 15.x...

I'd been using the Volts/.5 per this thread...

Duh.

While typing this I decided to RTFM....we made a mistake an hooked up the yellow (simulated narrowband) output to my ac switch. That's why adding 13.6 worked to get 14.7...narrowband on the LC1 gives .1v output at 15.0 afr, 1.1v at 14.0 afr and thus .5 at 14.7 - so .5/ .5 = 1 plus 13.6 so it was showing 14.6-14.7 at 14.7... that's what narrow bands do. DUH!!! No wonder it was getting 15+ readings at 12.3 real AFR...the narrowband output is 1.1 at 14.0 so 12.0 was off its scale.

I'll swap for the brown wire tomorrow and that shoud get me squared up. Maybe my mistake will help someone else figure this out before they pull out their hair like I was doing.

And the LC-1 has a range from 7.35 to 22.39 so I need to use Volts/.332+7.35 (per 2000C-5's post above).

I'll get this figured out one of these days.

Joe_G

OK success. I hooked up analog output 1 which is by default a narrowband emulator to my AC sensor. So it read fine at stoic but not off stoic. That was a mistake, and the wires are a pain to get at where we tied up the controller (behind the windshield washer bottle).

You can program the outputs but I about pulled out the wideband by the wires as I couldn't get it to "take" the programming. It's a finicky thing.

Here's the deal. I was programming output 1, then going to output 2, then back to output 1 and it would reset. Then I would exit, not programming anything. And it needs a free air calibration every time you program it which is a huge pain. (I blew up my cutouts with a leaf blower for a long time to get free air up there and waited hours between programmings). Finally I changed output 1 and hit program then exited the program. That worked.
I changed output 1 to have a range of 0V for 7.35 AFR and 5V for 22.39 AFR.

By the way if you note that range, the 7701/.5+10 does not work for the LC-1. That's what an AEM uses. Here's the proper equation for an LC-1.

Remember (thanks 2000C5):
VOLTS / (VOLTAGE RANGE/DEVICE RANGE) + (MINIMUM VALUE OF DEVICE READING) = AFR

The LC-1 goes from 0-5 v and has a range of 7.35 AFR to -22.39 AFR. So the equation is: note (22.39-7.35=15.04)

VOLTS / (5/15.04)+7.35 or

(VOLTS / .332)+7.35

Now HP Tuners matches up to my XD 16 properly and I can log AFR.

Hope this helps somebody.

5 Liter Eater

Joe, While the LC-1 CAN read from ~7 to ~22 I would say you're losing resolution for not much gain. I would configure it to 10-20 AFR, and even that is pretty wide. If you're tuning an NA application then you really only need ~11 to 17. The tighter you can get the range the more resolution you get and also the less prone to ground offset.

Joe_G

Bill, thanks again for all your help on this. It seems to be working great and I had such fits getting it set up yesterday I want to leave it alone. if anything, I'd prefer it had less resolution - the gauge moves so fast I'd prefer a more average reading. I thougth I'd set it up to sample 1/3 of a second (it can do instantaneous which reads each exhaust pulse) but perhaps I didn't. But I'm leaving it alone.

Here's a screen shot of my Scanner setup which shows my table of items I'm tracking and the PID I've set up to the left. Note the formula in the LC1AFR parameter.

5 Liter Eater

The better resolution just breaks down the 0-5V into a more usable range making it more granular. Do you really care if the car is running at 7.5:1 or 10:1? No! It's pig rich at anything less than 11. The update speed is dependent on the number of PIDs you're logging. BTW, with all the PIDs you're logging you're using 29 bytes of "bandwidth" which is cutting your framerate in half. Keep it under 28 to maintain 10 frames per second. Lastly, I remember reading something about 1/6th of a second being the ideal setting. http://www.hptuners.com/forum/showthread.php?t=2941)

Joe_G

well...ok. I'll give it a shot.

user_name

Great information in this post. Thanks to everybody who posted up their experience as I ran into each problem.

I'm using an autometer cobalt wideband A/F gauge. I had to calibrate the range before the values I had to put in made any sense. I ended up programming the range from 10-20. Also, this is a 0-4v gauge

However, I am seeing 12.2-12.4 on the gauge and 11.8-12.0 on the histogram.

The PID I am using now is ([PID.7101]/.4)+10.

Could any of you with experience recommend a value that might offset the readings just enough to match the readings on the gauge. I need hptuners to read .3-.4 higher.

95BlueBomber

To make it read .3-.4 higher just change the 10 at the end of the equation to 10.3 or 10.4

[ion] C2

Great write up, AFR is read perfectly with my AEM UEGO and A/C Pressure Sensor on my Alero, however, I'm surprised no one else has reported any issues with deceleration and idle performance (and maybe even all other aspects of driving). It seems the PCM sees the fluctuating voltage, or high voltage, and attempts to adjust the idle and other driving conditions based on that it's seeing that the A/C system is active and should be drawing load on the engine, but it's not, so my idle bounces all over if revved, and while cruising and decel the idle tends to bounce up and down as if cammed. Also, the fans are forced on all the time when tapped into the A/C pressure sensor, since it sees the high voltage and thinks the A/C is on, it turns the fans on.

If I start the car with the wideband connected to the A/C, it'll rev up as usual, then spike/hunt when the fans kick in and I assume the PCM thinks the A/C's on and fluctuating voltage when the AFRs change so it tries to correct it and it doesn't need to. If I start it without the wires connected, car acts perfectly normal. The instant I touch those two wires together (A/C pressure wire and wideband 0-5v output) the fans kick on and the idle starts hunting and bounces around if revved.

So.. it seems my only other option is to tap into the EGR pin. I have the wire and the diagram and know what to do, but it's a pain. It's too bad the A/C way of doing things screws things up. No one else has had this type of issue? Your A/C systems disregard the fluctuating and high voltage that the A/C pressure wire going into the PCM now reads?

user_name

I turn the AC off when tuning with the wideband. I have not had any problems.

[ion] C2

My A/C is off, in fact, the compressor is disconnected too. So is the A/C sensor. But the PCM still is seeing the heightened and fluctuating voltage from the A/C sensor since it's actually the wideband's reading, and then the PCM acts on that information. I wonder what would happen if I set my A/C disable RPM to 0, so A/C is automatically disabled no matter what. (My A/C is dead anyway) But I hear that only affects whether the compressor turns on or not.

user_name

My car is almost 100% stock and M6 so I don't notice any changes. Idle speed is set the same with the AC on and OFF. If you look at the idle airflow tab in hptuners you can see where it makes adjustments based on AC. I would think manipulating those settings would fix your problem. It might take some trial and error, but considering you AC is not hooked up, I doubt you could do any damage.

Joe_G

The line to my PCM for AC pressure has a toggle switch - one setting it's reading actual AC pressure and the other it's reading the wideband.

I don't run the AC when I'm logging wideband and it runs perfectly. If I forget to switch it back to AC pressure when I'm done logging, the AC doesn't work properly (goes off prematurely) but the car still runs perfectly.

The switch is a handy feature.