Booster/Aux Espar Heater DAD Communication?

220629

Well-known member
I've not been able to access my Espar Booster Heater at all with my DAD. Mine doesn't even see that the module exists. Has anyone been successful with Espar communication using the DAD?

The reason that I ask is I am considering just chopping the Espar Data Link wire and replacing it with a weatherproof fuse holder. I want to eliminate any possible Data corruption from the Espar. A fuse can be easily installed to re-establish the wire if ever needed.

I'll likely try this anyway, but if nobody has been successful communicating using the DAD that will seal the deal for me.

vic
 

Kubbie

'06 2500 140" Std Roof.
Isn't it true that after a number of failure to fire, the Espar locks itself out and needs to be reset with an MB star tool?
My guess is that there is communication, just not visible through DAD?

I dunno, but I'm not that brave to chop it.
 

220629

Well-known member
You bring up some good points.

There is communication provided via the Data Link conductor to the dealership level scan tools like the DRBIII or possibly Star (JD Caples would be the one to know about the other than DRBIII possibilities.)

Isn't it true that after a number of failure to fire, the Espar locks itself out and needs to be reset with an MB star tool?
I've read that. From my research that may be the mode of a native Espar diesel fired heater. I've read that after so many start attempts the native Espar heater locks out and needs to be reset using the proprietary Espar access scan tool. OR maybe the permanent lockouts are related to specific component failures which are monitored by the Espar computer and people assume it has locked out related to a couple start attempts. :idunno:

My Experience:
My 2004 heater main burner never fired for the first 6+ years that I owned my van. I tried it more than a few times over the years. Each time the most I would get was white smoke = unburned fuel. The Ignition Air Duct was plugged solid so the main burner never fired. When the button was pushed the red dash LED would light, the heater would try to start two times in succession and then would lock out, but not permanently. After an engine shutdown and restart it would again give two white smoke cycles.

After I cleaned the burner and screwed up the screen "wick" metering into the glow plug chamber I tried many more x2 white smoke cycles. There was never a permanent lockout. The heater runs fine now.

So, my experience shows that the Sprinterized Espar control module doesn't lock out for the (x2) failed ignition as described for the native Espar control.

My guess is that there is communication, just not visible through DAD?
And you very well may be correct. I'm going on the concept that the Espar module (computer) controls the burner completely as a stand alone unit. The Pin #6 & 7 "enables" are the only critical communication from the Sprinter.

If the Espar is communicating with the ECM or ATC via the Data Link conductor as you suggest then if I cut the wire that may stop my new happy association with my Booster Heater dead in its tracks.
I dunno, but I'm not that brave to chop it.
It may be an idiotic thing to do that and I'm just the idiot needed to give it a try. My ace-in-the-hole is that even without the DAD I can probably still get my buddy to connect the DRBIII to my Sprinter and reset things. I hate to bother him though.

Maybe I'll wait for warmer weather to try this. :rolleyes:

Sorry to go on. vic
 
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bc339

New member
Vic, the DAD has the capability to read the Espar, but only for Sprinters everywhere else that the US. The ECU does not lock it out, the Espar control unit does. So, a MB DRB III or Espar code reading device is needed. The 7 day timer has the capability, but is not wired. This is why I rewired mine to be able to read and clear the fault codes. https://sprinter-source.com/forums/showthread.php?t=24416

On the Espar main connector, the blue/white wire at pin 5 is the diagnostics lead that communicates with the ECU.

Bruce
 

220629

Well-known member
Bruce,
Thanks as always for the input.

... The ECU does not lock it out, the Espar control unit does. ...
Based upon that comment and my experience then I will say that the x2 failed ignition attempts of itself does not permanently lock out an Epar heater. It must take more than that to make the Espar computer unhappy enough to lock out the heater enough to need Espar scan tool type reset.

...On the Espar main connector, the blue/white wire at pin 5 is the diagnostics lead that communicates with the ECU.

Bruce
The blue/white Pin #5 data communication wire is consistent across the Espar schematics I've reviewed. The Pin #5 is also verified in the Sprinter Service Manual schematics.

I don't have the timer module.

Whoa!!!! "This is why I rewired mine to be able to read and clear the fault codes."
So you basically clipped eliminated that wire from the Sprinter Data Link and have no Espar operation issues. That's good news. :thumbup:

vic
 
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bc339

New member
I released the connector and put heat shrink over it so it wasn't a permanent modification.

Bruce
 

220629

Well-known member
I released the connector and put heat shrink over it so it wasn't a permanent modification.

Bruce
I expect that you would do it correctly. :cheers:

I'm the butcher who will cut the wire and install a weatherproof fuse holder as a Mickey Mouse connection point.

The important news for me is that the conductor is no longer connected to the Sprinter communication and the heater still works as it is supposed to.

Thanks again. vic

Edit: Getting the Espar to communicate may be related to powering Pin #6 or #7 to trigger communication with a DAD. No data for that, just a guess. Some discussion is here.
https://sprinter-source.com/forums/showthread.php?p=281118#post281118

The DAD does list the Espar in the options menu. My DTC Record Sheet lists CHM down near the bottom of the module listing. That listing is the order which it displayed on my DAD screen.

DTCchart2sm.jpg
 
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seans

Member
Vic, the DAD has the capability to read the Espar, but only for Sprinters everywhere else that the US. The ECU does not lock it out, the Espar control unit does. So, a MB DRB III or Espar code reading device is needed. The 7 day timer has the capability, but is not wired. This is why I rewired mine to be able to read and clear the fault codes. https://sprinter-source.com/forums/showthread.php?t=24416

On the Espar main connector, the blue/white wire at pin 5 is the diagnostics lead that communicates with the ECU.

Bruce
I'd like to revive this thread to learn if it is possible to read codes from the heater booster with a DAD and without the 7 day timer. The Dodge Sprinter schematics show the Espar's data line and several other devices all wired to the OBD-II connector's pin 15, IIRC. What's different between the US and European models that makes is possible for the DRB-III to read the Espar but not the DAD?
 

bc339

New member
The quick answer is the level or ability of the DAD software to communicate with the ECU. It has the ability, it's just the code wasn't written to allow the communication.

Bruce
 

seans

Member
The quick answer is ...
I'm curious about the long answer. I was poking at the ISO 14230 (KWP2000) spec and it seems it would be easy to implement both hardware and software on an Arduino. From a web search it appears that the heater booster uses KWP2000. Is there a difference between the US and European versions in that they use or expect different source and/or destination addresses, for instance (something that would require an Arduino)? Are they connected to different diagnostic connector pins (something that could be addressed by swapping pins in a patch cable inserted between the DAD and the Sprinter)?

{edit} The heater booster connects to pin 15 of the OBD-II connector. In Europe, a round connector is used. This post shows the pin mapping. BUT... there isn't a pin on the round connector that corresponds to pin 15 on the OBD-II connector (at least in that diagram.) So I guess the first step would be to determine which pin the DAD thinks the Espar is connected to. If it is trying to talk on anything but pin 15, that may be the issue. Time to break out the oscilloscope.
 
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seans

Member
Hooked up a scope to pin 12 and also pin 15 of the OBDII connector, and compared communications to the CTM, IC, and HBM on both pins. It looks like the DAD is talking on both pins simultaneously (which was a surprise, but I guess if the modules are addressed, why not?) I can't tell which way data is flowing without building a circuit, but it does appear that the DAD is making an attempt to communicate to the HBM. I can't tell if the HBM is responding and the DAD is unable to read it, but it is possible that the heater booster is simply not responding because the target address sent by the DAD is not the one in the heater booster. Ugh.
 

seans

Member
Finally able to look at data over the wire. Looks like the DAD sets up comm with the heater booster but then takes a while to get around to issuing the command to read the codes. It appears the heater booster times out before that, drops the connection, and doesn't respond to the DAD's subsequent requests.
 

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