Advertisement
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Home Who's Online Today's Posts HP Calculator CompD Gift Shop Mark Forums Read
Go Back   Competition Diesel.Com - Bringing The BEST Together > Tech Area- Dodge > EFI Live Tuning Discussion (Cummins)
Register Members List Timeslips EFI Live Library Invite Your Friends FAQ Calendar Mark Forums Read

Closed Thread
 
Thread Tools
Old 04-02-2019, 07:12 PM   #1
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
CM849 Barometric and ambient temperature

I installed a 2897333 (6.7L) combination sensor on my "bench" harness.

I can't get my CM849 to display anything other than 8psi baro and 160 degrees ambient. I've tried to rescale the baro. It isn't changing.

I have the same sensor connected to the intake horn and it reads correctly, albeit I have 5psi of boost due to the incorrect baro. Temp is 2 degrees higher than ECT cold soaked.
So, I duplicated the intake pressure scale for the baro. Still at 8psi.

I don't understand how the voltage axis works?

Can someone post a screen shot of a "deleted" baro sensor? I would like to keep the input for mountain driving. It may not play that great a role, but I don't want to find out that it matters while I'm away from home.

Thanks
Kyle

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250
 
Old 04-03-2019, 05:52 AM   #2
ComnRailPwr
 
ComnRailPwr's Avatar

Name: ComnRailPwr
Title: Too Much Time
Status: Not Here
Join Date: Jun 2009
Location: Stoutsville , OH
Member`s Gallery
Posts: 3,293
I'm having trouble following you. So you're using a 5.9 ECM but are trying to use a 6.7 barometric sensor but you also want to delete this sensor? I have had zero problems rescaling the baro sensor for my truck. I repurpose the barometric pressure inpput for low side fuel PSI. I'm using an aftermarket transducer rather than a factory baro sensor. I no longer use the ambient air temperature sensor. My application is a 6.7 common rail running 5.9 electronics. I relocated my ECM to the cab so I built my own engine harness. I'm pretty familiar with the 5.9 harness and repurposing sensors. Just not exactly sure what you're asking for. Deleting the sensor is just simply turning off the DTC codes for the sensor and not using it.

Last edited by ComnRailPwr; 04-03-2019 at 05:54 AM.
 
Old 04-03-2019, 08:42 AM   #3
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
I jumbled that one.

I want to try and figure out how to rescale first. (I've tried and failed)

If that doesn't work, I need to delete it.

I'm suspicious this ecm was sold because the baro input is damaged.

I couldn't find the ambient temp input to scale it?

I've done what you have, 5.9 ecm, 6.7 peripherals. I built the harness(es).

I've turned some dtc's off.
Does that still leave the ECM calculating boost from a false baro reading?

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250

Last edited by biggy238; 04-03-2019 at 08:55 AM.
 
Old 04-03-2019, 08:57 AM   #4
ComnRailPwr
 
ComnRailPwr's Avatar

Name: ComnRailPwr
Title: Too Much Time
Status: Not Here
Join Date: Jun 2009
Location: Stoutsville , OH
Member`s Gallery
Posts: 3,293
You may be on the right track. Scaling it is just as easy as changing the numbers in the axis. Michigan ACM sent out play farkle reference. The resistors in the sensor change that voltage based off temperature and that is the signal that's going back to the ecm. The ECM then interprets that signal and references the numbers that you punch in to that table.
 
Old 04-03-2019, 10:52 AM   #5
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
I will post a shot of the axis table when I can get back to it.
I hit both circuits with a pot and monitored them in EFI (also used a cts2) and it never reacted.

These are from the 6.7 file I was using to compare my 5.9 file to.

I moved the floor on my 5.9 file up to 60.2 kPa but no change. Click the image to open in full size.Click the image to open in full size.

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250
 
Old 04-03-2019, 05:50 PM   #6
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
OK so this was self inflicted. I was off one pin at the ECM and had the signal wires swapped at the sensor. I'm sitting on 13.9 on inlet and intake pressure and temp matches ECT. Click the image to open in full size.

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250
 
Old 04-03-2019, 05:59 PM   #7
ComnRailPwr
 
ComnRailPwr's Avatar

Name: ComnRailPwr
Title: Too Much Time
Status: Not Here
Join Date: Jun 2009
Location: Stoutsville , OH
Member`s Gallery
Posts: 3,293
It's always staring right at you
 
Old 04-03-2019, 08:39 PM   #8
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
How concerned do I need to be with the 13.9psi ambient readings?

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250
 
Old 04-08-2019, 06:10 PM   #9
Thekid760
 
Thekid760's Avatar

Name: Thekid760
Title: Too Much Time
Status: Not Here
Join Date: Jun 2008
Member`s Gallery
Posts: 475
Quote:
Originally Posted by biggy238 View Post
How concerned do I need to be with the 13.9psi ambient readings?

Sent from my SM-G950U using Tapatalk


Depends on your local conditions and altitude.

13.9 puts you roughly at 1500ft.


Sent from my iPhone using Tapatalk
__________________
95 3500 4x4 5spd 4.10
 
Old 04-09-2019, 01:39 PM   #10
biggy238
 
biggy238's Avatar

Name: biggy238
Title: Too Much Time
Status: Not Here
Join Date: Aug 2008
Location: Just North of Wrong
Member`s Gallery
Posts: 10,820
I should be at about 14.5 here.

Sent from my SM-G950U using Tapatalk
__________________
Check out @bdmaximusworx

05.5 Campanella White TDi Jetta 5spd 45.5MPG
-Little Sexy
'10 Silver F250 CCLB 4X4 6.4L cummins Swapped
Insta @trash.panda250
 
Closed Thread

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:32 PM.

 


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2006 - 2024, CompetitionDiesel.com
all information found on this site is property of www.competitiondiesel.com