Espar (Eberspacher) D2 "No Signal" After running for hours

Hi All -

I am having a problem I can't seem to fix on my espar D2 heater with easystart timer. The heater starts up and runs without a hitch. Then after about 5-6 hours of run time it turns itself off with the error "No Signal" displayed on the controller. I can turn the controller on and off and it maintains 'no signal'. But if I pull the fuse on the controller and then restart it it immediately starts up and will run again for 5-6 hours without a problem.

In previous winters, I was getting random errors when it was really cold and the heater was running on turbo mode for long periods of the time. It would kick off with error codes relating to fuel. I thought this might be in relation to my fuel intake routing or altitude so I changed the routing and installed the high altitude sensor into the mix (since the errors only happened when it was really cold outside and I was above 6,000 feet).

Since this fix I haven't gotten any more recorded errors, but I have repeatedly gotten the "No Signal" error. And it really is like clockwork after 5 or 6 hours of usage that it shuts itself down. Every night around 3 or 4 am when we are camping it turns off. I wake up with cold toes, reset the van power (essentially hard restarting the heater) and it turns right back on again and runs just fine till morning.

I've included a couple pictures of the wiring harnesses, for reference.

Thoughts?
 

Attachments

sprint2freedom

2008 NCV3 170ext
Related thread:
https://sprinter-source.com/forum/showthread.php?t=44592
I was getting NO SIGNAL Codes as well somewhat often and after talking with Espar Canada, realized I had two "extra" wires connected in between the D2 harness and controller. I clipped them and no codes since.
Maybe re-check your wiring?

Edit: I'm looking at the schematic I drew up for my install and I specifically noted that the yellow wire and whrd wire from the 16-pin connector were left unconnected. It looks to be connected at both sides in your photos. I have the EasyStart Select, but the altitude sensor has 3 wires in (rd/bn/buwh) and 3 wires out (rd/bn/buwh), the EasyStart controller has 3 wires in (rd/bn/buwh), and there are three wires (gyrd/bnwh/gy) going to the external temp sensor.
 
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Great! Thanks for the quick replies folks. Based on what I am reading it sounds like the yellow wire I have connected is in error. I will cut it and see if that solves the problem, then report back.

I had been reviewing the fault codes, but the 'no signal' error was actually not throwing any fault codes on the diagnostic screen.

Thanks again!
 

highsierrabear

New member
Maybe check your Time out settings? Just something else to investigate. I wrote about it a bit on my blog in the Espar installation. Your Easy Start timer settings may be different.
 

Midwestdrifter

Engineer In Residence
Any resolution? Mine started doing this randomly, and now, after pulling the fuse the controller won't recognize the heater. Applying 12v to the switch on signal turns the espar fan on. So the ECU is working, at least partially.
 

sprint2freedom

2008 NCV3 170ext
Any resolution? Mine started doing this randomly, and now, after pulling the fuse the controller won't recognize the heater. Applying 12v to the switch on signal turns the espar fan on. So the ECU is working, at least partially.
Cut.. the yellow.. wire!



Based on the blog entry here, that seems like it may have been resolved the issue, but OP ought to confirm.

Note: I had the yellow wire connected through the high altitude sensor initially, this appears to be incorrect. The heater was working, but I was getting occasional ‘no signal’ errors. Will report back once this new wiring has been tested out more significantly. However, per the wiring diagram to the right, DO NOT CONNECT THE YELLOW WIRE.
 

Midwestdrifter

Engineer In Residence
I never had the yellow wire connected, so that's a no go for me.

After a bit of testing and some research, I believe my D2 has a faulty ECU. I can hear the ECU come out of sleep mode (relay clicks) when I power up the Easystart timer, but it doesn't communicate. The second heater comm line does the same thing.

I will connect my D5 heater up just to make sure the easystart is not faulty. After some reading I have found that some heaters will overheat the control unit, but not throw a fault code. :idunno: Ambient temp never seemed to have any effect on the no signal errors in my case, so I may have had a faulty ECU from the start, and it just finally bit the dust.

Just to make sure, I am going to modify the ducting to reduce any flow restriction on the heating air outlet.

A new ECU is around 250$ I think. Of course getting one in Australia would be challenging, as alll Espar stuff is through Dometic, and they are basically crap for support.
 

Midwestdrifter

Engineer In Residence
I think I fixed it. Long story short, the one wire bus espar uses for digital communication is sensitive to high resistance connections. The main plug for the easy start timer was the culprit. I will be replacing it in the near future.

Fyi, the EST WILL REPORT no signal any time the primary heater can't be found, even if the secondary heater is working fine. Go figure...
 

GeorgeRa

2013 Sprinter DIY 144WB
Congratulation, thank you for the update. For, hopefully not required, $250 D2 ECU getting a new D2 could be justified for spare parts. Was the high resistance from the get go or due to some corrosion?

George.
 

Midwestdrifter

Engineer In Residence
Sigh, I spoke too soon. It's back to its old tricks. Basically either the EST or my ecu is fubar. I need another controller to test, so I will try to track one down.
 

Midwestdrifter

Engineer In Residence
Okay, mystery solved. Part my own ignorance (always test one thing at a time) and partially Espars spartan documentation.

First note. If you have the AD (second heater) enabled, the Easystart Timer (EST) will show NO SIGNAL, and prevent usage of either heater if one of the heaters is not communicating. By entering the workshop menu, and viewing the diagnostics, you can tell which heater is not communicating.

When I disconnected my D5 for service, the EST didn't notice right away. But when I cycled the power to clear the NO Signal fault due to the D2, the EST could not find the D5, and threw a wobbly. I reset the EST to factory settings, and it detected the D2 right away.


Second; I believe the D2 is cutting out (it still shuts down properly) due to the ECU overheating. This is different than the normal overheat, which occurs in the combustion chamber. Basically, the under seat space gets warm with the heater running on low, when the heater cycled to off then to on, the warm air under the seat heats the ECU (mounted right after the blower), and its shuts down. No codes are thrown. If I leave the side cover off the pedestal, the overheat doesn't happen. Note that I already have enough vent space per espar rules. This ECU overheating apparently is a problem with the newest D2 design, and can be very hard to diagnose. :idunno:

I am going to shorten the amount of duct under the seat in an attempt too reduce heat build up, but for now it seems to be working fine with the pedestal cover removed. Time will tell.
 
I am glad your issue with the espar have been solved Midwestdrifter! Unfortunately, I keep on fighting with the 'no signal' error. It goes away for a little while - then comes back. I thought I had fixed it when I cut the yellow wire, but that doesn't appear to be the fix.

I am not sure I understand the overheating issue or if this is the same as my 'no signal' issue. I have checked resistance across my connections and everything appears to be well connected. The problem remains the same - heater runs just fine for 5 or 6 hours, then all of a sudden (in the middle of the night) it throws a 'no signal' error. The error cannot be reset by power cycling the EasyStart timer. Only by unplugging and replugging the timer unit (resetting everything back to 'init').

I'll try operating with the side door off of the seat pedestal, to see if that helps, as midwestdrifter suggests. But other than that, I am all out of ideas.
 

Midwestdrifter

Engineer In Residence
When the no signal occurs, apply 12v to the D2 yellow line. Does it's fan turn on? If so the D2 ecu is at least nominally working.

You have three possible causes. The EST is faulty, the wiring is faulty, or the D2 ecu is faulty. I suggest cleaning and checking all the connectors. Reposition them to changr the stress on the wires. Put some dielectric grease on the contacts.

Running a bypass jumper directly from the D2 main harness to the EST, bypassing the other wiring may be a useful diagnostic tool.
 

jmvan

2017 144 Crew DIY
Running a bypass jumper directly from the D2 main harness to the EST, bypassing the other wiring may be a useful diagnostic tool.
What do you mean by running a bypass jumper directly for the D2 to the EST? Would you have to cut the wire bundle at each end and splice in?

I installed my heater this summer, had things working, rearranged where my electric cabinet was installed and somehow disrupted the heater. My easystart now goes from Init to No Signal. Any suggestions?
 

Midwestdrifter

Engineer In Residence
What do you mean by running a bypass jumper directly for the D2 to the EST? Would you have to cut the wire bundle at each end and splice in?

I installed my heater this summer, had things working, rearranged where my electric cabinet was installed and somehow disrupted the heater. My easystart now goes from Init to No Signal. Any suggestions?
Yes, I mean running a wire from the D2 harness directly to the EST blue/white wire, bypassing all the plugs.

You dont need to cut the wires, and needle probe through the insulation will work. A test lead with alligator clips and a needle through each wire will work.

Since you have No signal at all, you probably have a open somewhere in the blue/white wire. Either that, or your D2s ECU is not getting power. You can test the D2 by applying 12V to the yellow "switch on" wire. The D2 should start running its fan. It won't start heating, as you don't have an analog thermostat hooked up.

FYI, the EST should ideally share the same ground as the D2. This prevents ground voltage offsets which can happen in wiring.

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An Update on my ongoing No Signal issues. It continues to be very intermittent. Recently My D5 heater has also started having No signal errors right after startup. It is repeatable. Interestingly, the EST will resume communication on its own after a few minutes, without a reset (unlike the D2).

I have given in, and ordered a new EST from Heatso (140$). Hopefully that will be the final fix!
 

Midwestdrifter

Engineer In Residence
New EST is installed. Time will tell, but the error seems gone. I suspect the old EST had problems suppressing noise on the signal lines, but who knows.
 

jmvan

2017 144 Crew DIY
I tracked down my issue as a lose connection in the plug between the EST and the wire bundle. Basically I gave it a wiggle and things started working again. I took the plugs apart, didn't see anything amiss, reassembled and things are working.
 

Midwestdrifter

Engineer In Residence
I tracked down my issue as a lose connection in the plug between the EST and the wire bundle. Basically I gave it a wiggle and things started working again. I took the plugs apart, didn't see anything amiss, reassembled and things are working.
That was my initial thought as well. After removing or bypassing just about everything, I had to admit defeat. :idunno:
 

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