Looking for a LT4 log with SCIAP Vacuum and Pressure in the channel list.

[Alvin]

I wired a Positive displacement LT1 car for a SCIAP and the results do not look correct (stays at 97kPa)

I'm not sure if this is a error in the scanner or what.. A log of a LT4 car should let me know.

Please log Supercharger Inlet Pressure and Supercharger Inlet Vacuum. Don't even need to drive it.. just crank and rev a few times.

[pisces_0]

Sorry for the late reply, Alvin. Please see attached. Quick log of idle and into some boost.

2016 Suburban, L83, SCIAP pressure and voltage recorded in the log.

[Alvin]

That's so odd. My sensor voltage changes also... and it totally fixed the driveablity issue but the SCIAP pressure stays the same always.

[Alvin]

Here is a log file using your channels just in case I grabbed the wrong pid or something.

Here is also the file.. Perhaps I didn't turn something on like I should have? I think i got it right.. Like I said huge difference in driveablity. It seems like it works but in the log it doesn't look like it works.

Should I have enabled some DTC's or something? Mind having a look at this?

Edel tune SCIAP added.hpt

Edel tune SCIAP added.hpl

[pisces_0]

After installing the SCIAP sensor I had to run Repoll For Supported Parameters in the scanner for it to display.

[pisces_0]

Under Engine Diag->Airflow->Supercharger Inlet Air Pressure, your High Volt Test & Low Volt Test are both correctly set to Enable.

I missed this initially when I did the install and it wasn't reading pressure or voltage off the sensor.

[Alvin]

Under Engine Diag->Airflow->Supercharger Inlet Air Pressure, your High Volt Test & Low Volt Test are both correctly set to Enable.

I missed this initially when I did the install and it wasn't reading pressure or voltage off the sensor.

So I take it you didn't see anything out of place in the tune I uploaded?

[pisces_0]

So I take it you didn't see anything out of place in the tune I uploaded?

No, nothing different that may affect SCIAP performance. All the main settings are correct.

[Alvin]

Thanks.. I must be some sort of scanner issue.. repoll or whatever. It was clear that it fixed the car. Huge difference.

I didn't turn on any DTC"s for it. Is the only thing I could think I didn't do that maybe I should have.

[will_974]

Hey,
I just went through this.
If VCM scanner is showing 0 for SCIAP pressure sensor
Most likely the Linear and Offset are not set.

I was able to find these paramenters and had HPtuners add them to the latest beta

[ECM] 4013 - Supercharger Inlet Air Pressure Sensor Linear:
[ECM] 4014 - Supercharger Inlet Air Pressure Sensor Offset:

[blindsquirrel]

Initially the AC pressure sensor on my truck had the same behavior - voltage responded normally, but the pressure PID remained fixed. Support was able to fix it with a few revisions.

[Alvin]

Hey,
I just went through this.
If VCM scanner is showing 0 for SCIAP pressure sensor
Most likely the Linear and Offset are not set.

I was able to find these paramenters and had HPtuners add them to the latest beta

[ECM] 4013 - Supercharger Inlet Air Pressure Sensor Linear:
[ECM] 4014 - Supercharger Inlet Air Pressure Sensor Offset:

Thank you!! I knew the AAP linear and offsets were not making sense

[Ben Charles]

Finally Wired the SCIAP (1 bar Map) on my LT1 15 C7, repoll scanner as well. My LT4 Tmap is now stuck at 64KPA key on engine off and Supercharger inlet Pressure is 4.0 Volts in the scanner and does indeed go to 0 when I unplug it, so its reading something.. However Supercharger inlet Vac stays at 98 when running and supercharger inlet pressure stays at 0.
Not sure how TMAP is off now though????
Ill post log and current tune file if anyone has an opinion. Fairly certain tune file is right, but a second par of eyes never a bad thing.SCIAPTest.hpl
15VetteBENA8PI2.3FINALSCmapBen1.hpt

[GHuggins]

I'm going through this right now with a customers Ben. I was told to make sure all three settings under pressure were enabled along with the dtc's and to have it as supercharger equipped. Won't know until tomorrow if it actually got it working correctly. I just noticed your pressure settings weren't all enabled and your dtc's were active yet. The rest of it looks right.


EDIT - you should only have the top 2 settings under pressure enabled otherwise it sets a baro code... The rest of the corrections seem right so far.

[Ben Charles]

Thanks Greg, I’m actually at the car now lol (late night)

Going to activate AAP3 volt test to enable and set the P012B for the supercharger inlet pressure sensor performance. Be right back

[Ben Charles]

OK, just did some testing.. Interesting enough the normal Map sensor PID doesn't report correctly anymore shows 64 KOEO and roughly 2X running (The newer Style E92As I always have to use HI res, so odd I have too now on my car, but whatever. MUST USE Manifold Absolute HI RES, read 100 KPA KOEO.

Supercharger inlet Vac Stuck at 98 doesnt move when running
Supercharger inlet Pressure stuck at 4.0 and doesnt move when running.

At this point I think 2 pins need to be Flip floped, If I get a moment in the morning Im going to swap some pins around.

[Ben Charles]

ECM Modifications
X1 Pin 4 (TIAP Sensor Signal) -> move to X2 Pin 45
X1 Pin 5 (TIAP Sensor 5V) -> move to X2 Pin 64
X1 Pin 4 -> add Pin 1 on SCIAP Sensor Signal
X1 Pin 5 -> add Pin 3 on SCIAP Sensor 5V
X1 Pin 20 -> add Pin 2 on SCIAP Sensor Gnd



Wanted to question the pin outs here?
On the connector for the Sciap (simple 1 bar map)
Pin 1 should be 5volt reference
Pin 2 low reference/ground
Pin 3 map sensor signal


I copied this from another thread where I questioned it, I did what others have done, BUT IM 99% sure I need to swap Pins 1 and 3 and it will work.

The reason I believe MINE is different is I had my friend Bill at BP automotive make my harness and I told him just to wire it Like an LS3 sensor, I bet Pins 1-3 are opposite from the LT1 sensor (honestly assumed they would be the same?)

Alvin this was before you had your kit otherwise I would have just bought it..

[GHuggins]

My customer is using the kit you're referring to from pcmofnc and his was missing the 5v ref. He got that working by stealing it from elsewhere, but I was wondering about the pin hookups myself. All the E92's should be the same, so should use the same pins as the lt4. His is reading just like yours and can't tell a difference with it being installed. Didn't you have another one that was the opposite?

[GHuggins]

OK, so here is how a LT4 is wired

SCIAP -
X1 - Pin 5 - 5v ref (pin 1 on map)
X1 - Pin 20 - Ground (pin 2 on map) ------ > Looks like you're correct on the directions being wrong here - the 2 pins should be swapped
X1 - Pin 4 - Signal (pin 3 on map)

X1 - Pin 13 - temperature sensor input if running the lt4 map as I recommend since this will control timing adders.

[GHuggins]

More info fwiw...