Go Back   Sprinter-Forum > T1N Sprinters > T1N Talk

T1N Talk General Discussions related to T1N Sprinters.

Thread Tools Display Modes
Old 02-21-2020, 05:21 PM   #311
2004 140Ē SHC U.S. T1N
Nautamaran's Avatar
Join Date: Jan 2017
Location: Calgary, AB
Posts: 2,910
Thanks: 1,047
Thanked 2,032 Times in 1,312 Posts
Default Re: Who wants an Arduino-based Aux Instrument Panel?

I imagine that service station was a welcome sight!?

The “Fuel in Tank” number (top right, details page) is straight from the ECM. The data value ranges from 0-100 litres and I convert it to US gallons for the display.
The ECM gets it from the IC module via canbus. The IC determines the tank level by interpreting the variable resistance that it measures across the tank sensor circuit, which changes according to the floating bobber on the end of a metal rod. There’s a post in the “Crackinng the K-Line” thread tabling sensor resistance as I did a tank fill... the sensor flat-lines when it floats up against the tank top, so the IC is blind to the last 10 or 15 litres added, which is why the fuel gauge stays pinned at Full for the first few gallons burned. I expect it’s equally blind to the dregs once the sensor is sitting on the bottom of the tank, but I’ve never ventured that low - I try to avoid drawing it down too far since I don’t know how low fuel level affects the cooling performance of the fuel system... I keep a log and typically fill at 400 mile intervals, though I usually need a break long before the van does...

Nautamaran is offline   Reply With Quote
The Following User Says Thank You to Nautamaran For This Useful Post:
glasseye (02-21-2020)
Old 02-21-2020, 10:41 PM   #312
Join Date: Jul 2017
Location: Phoenix, AZ
Posts: 15
Thanks: 2
Thanked 16 Times in 6 Posts
Default Re: Who wants an Arduino-based Aux Instrument Panel?

Originally Posted by Nautamaran View Post
The fuel economy calculation requires the MAF and O2 sensor voltage, so a lack of fuel economy readout may point to a sensor problem? My readout sits on zero for a few (five?) minutes while the O2 sensor heats up (normal?) but is then quite stable, and within 10% of long-term consumption.


I sent some info out today to help start the cracking and adapting of the program to interpret 2003 OM-612 data, but since the OM-612 doesnít have an O2 sensor, Iím not sure that Iíll be able to provide a meaningful fuel economy value without first cracking the ECMís software lockout challenge/response algorithm.

I haven't been able to read it on any of the pages. And recently did a 5 hr drive so it's not about the distance.

It could be a sensor issue, I don't get any engines codes but have wondered if I have an issues with MAF or O2 for sometime. I guess it's time to replace them both and see if that helps.

Sent from my iPhone using Tapatalk
Gvnclk is online now   Reply With Quote
Old Yesterday, 03:10 AM   #313
'05 Box Snow Camper
vanski's Avatar
Join Date: Jun 2012
Location: SFBA, CA
Posts: 1,765
Thanks: 814
Thanked 750 Times in 535 Posts
Default Re: Who wants an Arduino-based Aux Instrument Panel?

The nautabox is going to be used by CARB before you know it...
vanski is offline   Reply With Quote

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

All times are GMT. The time now is 05:44 PM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.