NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #61  
Old December 30th, 2016, 17:28
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

The CPS produces it's own AC voltage if I'm not mistaken so it will only "read" when the engine is spinning. The Renix data stream does not give a raw CPS reading that I know of, only a reading that can be calculated into RPM which comes directly from the cps. So if you have an rpm reading, you have a cps reading.

As for the distributor sync sensor, it does read the camshaft, but it is not accurate enough to determine rotational angle, only if cylinder 1 or cylinder 6 is on the compression stroker. The ECU can run fine without it, but the ECU has to guess which cylinder is TDC before it can start.

Maybe I'll look into data logging and see what sensors read when to maybe throw some sudo diagnostic codes to check if sensors aren't reading.
Reply With Quote
  #62  
Old December 30th, 2016, 17:37
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

And jeep driver, the link won't go live untill new year's, I don't like that eBay won't let people view the link untill the date but I can't do anything about it.

You should be able to view the previous sale here though

http://www.ebay.com/itm/Renix-Engine-Monitor-Jeep-Scan-Tool-/262758283724?nma=true&si=BP4Sfc2rknaD%252BggFRsBxs Ng%252BFNA%253D&orig_cvip=true&rt=nc&_trksid=p2047 675.l2557
Reply With Quote
  #63  
Old December 30th, 2016, 17:48
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: Renix scanner port data question.

Nope, still can't view it.




............edit...................now I found you.




List an item just as you would and price it at $3K.......that won't ever end and you can use it to allow people to find you.


What is your screen name on ebay?

Last edited by Jeep Driver; December 30th, 2016 at 17:52.
Reply With Quote
  #64  
Old December 30th, 2016, 18:06
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

That's an idea, username is NickInTimeFilms, you'll be able to find anything I do through that name.
Reply With Quote
  #65  
Old December 30th, 2016, 18:24
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 697
Re: Renix scanner port data question.

So, let me ask you..........


If you figured out how to read Renix, can you program a new ECU for Renix?


Here's why I ask-

My neighbor just did an LS swap in a S10, he's got a guy that reduced his engine management harness from something like 190 wires down to 60 wires......stripped out a lot none sense, even removed the O2s.

Can you do something similar with Renix?
Reply With Quote
  #66  
Old December 30th, 2016, 18:49
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

Uh, if you're asking if the renix ECUs are reprogramable then that is a no. If the Renix ECU is removed then it's not really a Renix anymore.

As for installing an aftermarket ECU, it's very possible, you just have to know a lot about your sensors and how the new ECU will read them to run the engine . There is a fully programmable open source ECU already, I think it's called mega squirt or something like that.
Reply With Quote
  #67  
Old December 30th, 2016, 23:28
outlander's Avatar
outlander outlander is offline
NAXJA Forum User
 
Join Date: Oct 2004
Location: Columbus,Ohio
Posts: 3,796
Re: Renix scanner port data question.

I still have to instal the lastest update on my REM monitor after you changed the map to read volts.
Hopefully i wont have any probs with bootloader
Reply With Quote
  #68  
Old December 31st, 2016, 22:34
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

Long link if the first one didn't work: http://www.ebay.com/itm/Renix-Engine...850744&vxp=mtr
Reply With Quote
  #69  
Old January 1st, 2017, 17:03
outlander's Avatar
outlander outlander is offline
NAXJA Forum User
 
Join Date: Oct 2004
Location: Columbus,Ohio
Posts: 3,796
Re: Renix scanner port data question.

Hey nick so you changed the map readout to volts on the latest update?(need to get to a computer to instal)

So it was reading manifold pressure before right?

So basically the pcm shows both absolute pressure and map voltage at the diagnostic port?

Or is it as simple as the REM monitor interpreting what it sees based on the code you wrote for it ?

Just wondering....trying to better understand the renix pcm

Last edited by outlander; January 1st, 2017 at 17:07.
Reply With Quote
  #70  
Old January 2nd, 2017, 12:26
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

The REM only reads what the ECU sends it and will then do math to get actual readings. The only reading that the REM directly reads is the Oxygen Sensor Heater Relay Voltage, everything else is straight from the ECU.

Now there is a bug in the latest update becuase it was really only a quick patch but if you set the Pressure Unit to Voltage, the MAP will read as expected but the Vacuum is also affected by this and may read in BAR or something odd so I need a good work around. Setting the pressure to any other unit will read properly for MAP and VAC. I may add the voltage reading to the diagnostic menu or figure out what the best way to show it would be.

As for the ECU, I'll give you a quick overview of how it works.

All of the sensor are fed into the Renix ECU. The ECU will convert those analog readings into a digital value and then do the necessary adjustments to the engine for it to run appropriately.

Those Sensor Readings and Adjustments Values are then all grouped together and sent to the ECU Transmit pin on the diagnostic connector to be read. My REM reads the TX pin looking for the beginning of the stream and will then read the entire string in when found. You only need the TX and Ground pin in order to read all the info from the ECU.

Each piece of information is sent as a byte which is only a value from 0 to 255. The REM will do the necessary calculations to convert that 0-255 number into something more useful such as Voltage, or a unit of measurement. They are then displayed on the REM with some screen formatting so that they stay in place.


Now for example, let's look at the MAP reading.
The MAP byte is the 4th byte in the stream. When the engine is off this number will read very high, let's use 247 for example.

That number can be converted into:

Volts: _____247 / 51 = 4.84V
BAR: _____ 247 / 255 = 0.969bar
In Mercury: 247 / 9.13 + 3.1 = 30.15"Hg
KPA: _____ 247 / 2.7 + 11 = 102.48kpa
PSI: ______247 / 18.6 + 1.5 = 14.78psi

Now that will give you the Absolute Atmospheric Pressure from the MAP sensor.

In order to get the Relative Engine Manifold Vacuum we will need the help of another byte, the Barometric Pressure before engine start (#17 in the stream)

We will take the MAP reading and subtract it from the Baro reading so that the reading is zeroed at current atmosphere and you get a negative pressure reading, also known as a vacuum. Then we can convert it into our desired pressure unit.

So now, let's use 91 as MAP and keep 247 for Baro to get out vacuum reading:

BAR: _____ (247 - 91) / 255 = 0.612bar VAC
In Mercury: (247 - 91) / 9.13 + 3.1 = 20.19"Hg VAC
KPA: _____ (247 - 91) / 2.7 + 11 = 68.78kpa VAC
PSI: ______(247 - 91) / 18.6 + 1.5 = 9.89psi VAC


Alright, so hopefully I didn't pop any brains yet
Hope that clears anything up, if not I'd be happy to answer any other questions.
Reply With Quote
  #71  
Old January 2nd, 2017, 16:20
outlander's Avatar
outlander outlander is offline
NAXJA Forum User
 
Join Date: Oct 2004
Location: Columbus,Ohio
Posts: 3,796
Re: Renix scanner port data question.

Thanks I understand.
You've definitely done your homework Nick.
Reply With Quote
  #72  
Old February 5th, 2019, 01:23
outlander's Avatar
outlander outlander is offline
NAXJA Forum User
 
Join Date: Oct 2004
Location: Columbus,Ohio
Posts: 3,796
Re: Renix scanner port data question.

i actually like it reading pressure instead of volts.
all you need is a barometer app on your phone that tells you pressure at whatever elevation your at and the map reading from the rem module should be close.
having it read in volts is kinda redundant i realize now.
Reply With Quote
  #73  
Old February 5th, 2019, 11:39
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

Quote:
Originally Posted by outlander View Post
i actually like it reading pressure instead of volts.
all you need is a barometer app on your phone that tells you pressure at whatever elevation your at and the map reading from the rem module should be close.
having it read in volts is kinda redundant i realize now.
Exactly! Why worry about trying to do the math when a machine can do it for you!

On a more technical note, a straight voltage calculation could be inaccurate depending on how the system is wired.

The voltage calc assumes the reference voltage is exactly 4.98v, but if the ecu is having issues and is outputting a lower than usual reference that it is also internally calibrating to, then this voltage calc will be wrong and could cause more confusion then it would help.

The pressure readings will still be accurate in this case, however, as they are only a ratio from the reference voltage to ground and will read the same ratio regardless of reference voltage.
Reply With Quote
  #74  
Old February 5th, 2019, 16:30
outlander's Avatar
outlander outlander is offline
NAXJA Forum User
 
Join Date: Oct 2004
Location: Columbus,Ohio
Posts: 3,796
Re: Renix scanner port data question.

What version is the current rem,Nick?

What benefits do the current modules offer compared to the earliest ones?

I have one of the early ones and kinda feel like its border obsolete with all the fancier versions you've released...lol

back to the top with ya...
Reply With Quote
  #75  
Old February 6th, 2019, 16:06
NickInTimeFilms's Avatar
NickInTimeFilms NickInTimeFilms is offline
NAXJA Forum User
 
Join Date: Aug 2015
Location: NJ
Posts: 37
Re: Renix scanner port data question.

Quote:
Originally Posted by outlander View Post
What version is the current rem,Nick?

What benefits do the current modules offer compared to the earliest ones?

I have one of the early ones and kinda feel like its border obsolete with all the fancier versions you've released...lol

back to the top with ya...
Oh, boy... where to start, haha.

So currently I am up to the REM II+, board version 5.2. I am looking to release a clock panel version, as well as a JR base model some time in the spring-summer timeframe for people that want different options.

The REM II(v4) and above are built on a new microchip architecture which is better in almost every way; blows the original REMs out of the water. They can manage up to 4 datastreams at the same time, have a buttload more space for awesome program features, are much faster, have more professional circuity for robustness, and lot of add-ons and mod-ability for power users.

The v5 boards take it a step further with a fully embedded design for access to way more pins, and has a 3 channel fan controller and basic DMM features baked right in. They have gotten a little out of hand with features, but that just means I'll be busy coding new features for some time to come.

I almost feel bad for folks that are pushing along the old units, but it is a testament to their usefulness. At the very least, I HIGHLY recommend updating to the latest software because the last update was a huge overhaul that will make your unit feel brand new again.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
RENIX Data Logger yellowoctupus OEM Tech Discussion 26 March 15th, 2017 11:22
Renix data charts Lanthanaas OEM Tech Discussion 8 April 25th, 2015 20:04
Innovate LM2 Wideband O2 Sensor/OBD2 Scanner/Data-logger in DC gradon For Sale: Private Party Only. XJ ITEMS ONLY 4 June 26th, 2014 08:17
what is a good OBD II scanner with real time data mmag1982 Jeep Street and Performance 11 September 10th, 2011 07:26
Need A/C low pressure port for Renix pantera1973 SEC For Sale / Wanted Forum 1 June 27th, 2011 16:28


All times are GMT -7. The time now is 17:23.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014