Scan Gauge II XGauge - EGT & Boost

[Blue_Hen_TDI]

Are you adjusting for zero with engine off, or for zero at idle? I'm getting the impression (from the wisdoms of the interwebs) that by design our TDIs actually might make a little bit of boost at idle, to keep that little fan spinning and reduce turbo lag.

The ScanGauge stays on for a few seconds after the ignition is shut off and the boost reading doesn't drop any from idle. I'm not sure if the sensors are still active, but that's what I observe.

 

[VeeDubTDI]

The ScanGauge stays on for a few seconds after the ignition is shut off and the boost reading doesn't drop any from idle. I'm not sure if the sensors are still active, but that's what I observe.

Everything stops the moment the ignition is turned off. To check boost with the engine off, you have to turn the ignition on and then wake the ScanGauge up by pressing a button.

 

[JdC Machine]

Everything stops the moment the ignition is turned off. To check boost with the engine off, you have to turn the ignition on and then wake the ScanGauge up by pressing a button.

This. I watch for updates in the numbers after shutting the ignition off and nada. For those with an SEL with push-button start, just press the "start" button with your foot off the brake to turn the ignition on.

 

[brent_strong]

Do any of the scan gauges have a way to connect an additional OBDII device? I have the Valentine 1 OBD power plug hardwired for my V1, but would like to run the scangauge too...

 

[VeeDubTDI]

You can buy OBD cable splitters.

 

[JSWTDI09]

Do any of the scan gauges have a way to connect an additional OBDII device? I have the Valentine 1 OBD power plug hardwired for my V1, but would like to run the scangauge too...

You can buy OBD cable splitters.

Your car can only talk to one device at a time. However, if the only thing that the Valentine 1 is getting from the ODBII plug is power, a splitter will probably work OK. If the Valentine 1 actually communicates with the car, a splitter might not work. For example, you cannot have an ODBII gauge system (like a ScanGauge) and VCDS both working at the same time.

Have Fun!

Don

 

[brent_strong]

The V1 does pull a speed signal from the OBD port. Sounds like that feature would be disabled using a splitter.

Thanks for the info though!

 

[GeekDrew]

The V1 does pull a speed signal from the OBD port. Sounds like that feature would be disabled using a splitter.

Thanks for the info though!

I do exactly that -- have both a V1 and ScanGauge connected to OBD at the same time. Everything still works properly (yes, including V1 speed muting). IMO, everyone using a V1 should do this - *SO* much nicer than hard-wiring it any other way. I'm using this splitter.

 

[brent_strong]

Awesome! Maybe it's because the V1 is just scraping the speed signal, not actually doing any 2-way communication with the OBD port. Either way, I'm going to give it a go I think!

 

[Diesl]

Your car can only talk to one device at a time.

Why is that? Are the OBD scanners all defaulting to the same address? It's a bus, and the car has certainly more than one device on it. As long as the scanners/monitors are respecting the protocol it should work, shouldn't it? Linear Logic sells a cable for daisy chaining ScanGauges; is anybody using that?

 

[JSWTDI09]

Why is that? Are the OBD scanners all defaulting to the same address? It's a bus, and the car has certainly more than one device on it. As long as the scanners/monitors are respecting the protocol it should work, shouldn't it? Linear Logic sells a cable for daisy chaining ScanGauges; is anybody using that?

The CAN bus is a pretty simple bus. The problem is that all external communications (like the ODBII port) must go through the CAN Gateway (another controller on the CAN bus). This is the "bottleneck". The CAN gateway cannot handle multiple connections simultaneously. If there was an easy way to get directly on the CAN bus, your idea could work. As for scanners/monitors respecting the protocol, what might be able to work would be if the scanners/monitors respected each other and only opened a "communications channel" when needed. However, this would provide much "choppier" data.

Have Fun!

Don

 

[NickBeek]

Dialing from FF6F to FF54 took me down from +1.1 to -1.6 PSI at idle. After experimenting, I found that FF64 was the magic number to get me to 0.0.

Thanks! FF64 got me much closer to 0 with the engine off as well.

 

[Nebelwerfer]

Just thinking out loud....is there a way to keep tabs on the DPF ash load through the Scanguage?

I'm thinking there must be some sort of sensor for the computer to detect it so as to start the regen. If there is, it should be able to be monitored so it can give you a heads up on an impending regen.

Thoughts?

 

[Diesl]

Soot load, not ash load. The regens burn off the soot. You can't burn ash.

But it would also be nice to keep track of the ash load as well.

The scangauge can access what I believe to be the DPF differential pressure and the expected pressure (cf. My 'what is PID 7A?' thread). The expected pressure is a function of the ash load, and the ratio of the two pressure values times ash load might tell us the soot load. But this is all a guess.

 

[VeeDubTDI]

Very interesting thought - definitely a good question for the ScanGauge gurus.

 

[mlprater]

Well, the 'charge air cooler temperature' is available; that should be the effective intake air temperature (unless VW decided it should be something else, like the temperature of the intercooler housing - but that would be pretty silly).
Added:

TXD is 07DF01+PID 
name PID RXF     RXD  MTH          units   comment  
 ICT 77 04410577 3008 0001000AFFD8 ºC      intercooler/charge air temperature

What would the MTH be for Fahrenheit?

Thanks!

 

[Deezil_n_Dachs]

Installed ours today. Displaying water temp, boost, PID3C and EGT1. Hope the wife pays some attention to it while she drives around!

 

[Diesl]

Hope the wife pays some attention to it while she drives around!

Good luck with that....
Thankfully the car will run just fine without anybody watching the gauges.


Regarding C-to-F temperature conversion: there must be several examples of this already out there around here. You'd multiply by 9, divide by 50 (because you were already dividing by 10), and add 32. 9dec is 9hex, 50dec is 32hex, and subtracting 32 more when you are already subtracting 40 is -72dec = -48hex = +FFB8hex in two's complement, so that would make the MTH 00090032FFB8. If this blows up your scangauge or your engine, don't blame me.
And the next time somebody asks, it's your turn to explain it.

 

[VeeDubTDI]

Good luck with that....
Thankfully the car will run just fine without anybody watching the gauges.


Regarding C-to-F temperature conversion: there must be several examples of this already out there around here. You'd multiply by 9, divide by 50 (because you were already dividing by 10), and add 32. 9dec is 9hex, 50dec is 32hex, and subtracting 32 more when you are already subtracting 40 is -72dec = -48hex = +FFB8hex in two's complement, so that would make the MTH 00090032FFB8. If this blows up your scangauge or your engine, don't blame me.
And the next time somebody asks, it's your turn to explain it.

Thanks for the explanation! My high school science and math days are coming back to me now!

 

[Verilux101]

Can this be done with the X gauge instead of the Scangauge?

 

[VeeDubTDI]

XGauge is a function of the ScanGauge - it's the way you add a non-standard gauge by entering the PID codes and correction values.

 

[Verilux101]

Can this be done with the X gauge instead of the Scangauge?

Sorry, I meant the ultragauge.

 

[BPofMD]

Has ANYONE used the UltraGauge on the Passat Tdi ? From what I hear , you can NOT enter PIDs into the UG. WYSIWYG

 

[rotarykid]

Has anyone tried the GArmin "ecoRoute HD" in TDI??? I have one of these hooked up in 05 Accord.

It gives some readings that are similar to what my "ScanGauge II" does. No wires required from the OBD port to the Garmin device to get readings, uses a bluetooth signal to load info for readings.

I get pretty much the same the same readings in the Accord with both devices.


I haven't had a chance to hook it up to my 97 Passat TDI yet, I will be interested to see what kind of info I can get.....And I am interested to hear if anyone else has hooked one of these up to a TDI.....

 

[eyedunno]

I have an older Scan Gauge II, v3.16. I have been able to get Boost and EGT1 set up but have not been able to get EGT3, for regen, to work. Has anyone out there with this firmware version been able to get XGauge set up to work with EGT3? Maybe it's a function that is only available with a firmware upgrade? Any pointers are appreciated.

 

[Blue_Hen_TDI]

Why not just use EGT1?

 

[FormerOwner]

Gentlemen...

I am wondering if simply installing an analog gauge via drill & tap the exhaust manifold is a viable alternative that would be of benefit?

I've done this in a Cummins years ago... curiosity kicked in.

 

[JdC Machine]

Gentlemen...

I am wondering if simply installing an analog gauge via drill & tap the exhaust manifold is a viable alternative that would be of benefit?

I've done this in a Cummins years ago... curiosity kicked in.

It can be done. However, difficulty level will be far higher than doing so on a Cummins.

 

[eyedunno]

Why not just use EGT1?

From what I gather here using EGT3 is a good indicator when a regen is in progress. I'm not new to diesels but this is the first vehicle that has this function. Then again maybe I'm missing something about regen.

 

[JdC Machine]

I read EGT1 and it's not hard to tell when a regen cycle starts. Temperatures at idle will be 800+.