Mysterious ESPAR Malfunction

Our ESPAR isn't working. We have torn it apart and cleaned it. The glow plug works, the fuel pump works, all parts are accounted for and appear to be in good condition.

Is there a computer shutoff that could be keeping it from working?

The controls could be keeping it from operating. I assume you checked the 25 amp fuse under the driver seat.

A fairly easy test would be to jump 12 vdc to the Espar pin #6 and #7 enable. It should fire up.

Some info is here.

https://sprinter-source.com/forums/showthread.php?p=278359#post278359

vic

After several "No Starts", the ECU in the Espar will lock it out until the fault is cleared.
To clear the fault will require:

A. Access to a DRB III scan tool or equivalent.

B. An Espar shop with an Espar scan tool that plugs into the heater to read and clear codes.

C. A seven day timer wired to read and reset fault codes.

Bruce

Bruce,
I know that you really have excellent troubleshooting skills and a really great understanding of systems, but I feel compelled to modify your reply.

bc339 said:

After several specific problem "No Starts", the ECU in the Espar will may lock it out until the fault is cleared.

Click to expand...

My heater didn't fire properly for many start attempts over literally 4 years of infrequent attempts. I cleaned and repaired the unit to have it fire up and work properly. It didn't require any scan tool computer access. So... depending upon the failure mode, it may just need the proper enable signals to fire up.

That said, if a lockout has been set, I agree completely agree.

bc339 said:

To clear the fault will require:

A. Access to a DRB III scan tool or equivalent.

B. An Espar shop with an Espar scan tool that plugs into the heater to read and clear codes.

C. A seven day timer wired to read and reset fault codes.

Bruce

Click to expand...

vic

My van is a 2005 and has been in the Houston area its entire life. it only has 80k miles on it and looks new and drives like new and zero rust. It does not get/stay cold here very long so the heater should not have been used much. I have only owned it for 2 years. I never tried to turn on the espar unit until the end of last winter when I flushed the radiator. It fired up and ran perfect. This winter I tried to turn it on but it did not fire up. I searched all the threads on the espar here and discovered the auxiliary water pump was not running. I tapped on the pump and it started but the heater did not fire up after multiple attempts and it was not pumping fuel. I was too busy to trouble shoot it and really did not need the heater so I sorta left it alone, (I only use my van for recreation as did the previous owner). Well I am sort of OCD and like my mechanical things to be in top order so I had some free time last week and decided to disconnect the battery, (left it disconnected for about an hour) to see if it would clear the no start on the espar. Well it fired right up after this. It may be a coincidence but I would try disconnecting the battery. Also check the aux water pump.

After spending many hours rebuilding mine and finally getting it to work, I would (this doesn't add too much to above):

1. Test the 25 amp fuse for the Heater Booster under the seat (primary power)
2. Test the 10 amp fuse for the Heater Booster under the seat (I believe this is the dynamo pin but it's been a while so sorry if I'm mistaken here)
3. Push the REST button and put your hand on the water pump to make sure that's working
4. If it's still not working, yes, diagnostics is your next step if you've already cleaned the sucker out.

If you get a blower fan error but the blower fan spins freely there is a reasonable chance it's the Espar ECU which is $500 to replace. What a joke....

Based on my experience, Espar will run regardless of working or non working auxiliary pump, it just can get overheated as the flow of coolant is reduced at low rpm.

Oilburner said:

Based on my experience, Espar will run regardless of working or non working auxiliary pump,...

Click to expand...

That is true. The Espar heater gets an enable signal which has absolutely nothing to do with whether the aux electric coolant pump is actually operational or not.

That said, it is important that the electric pump runs when the engine is not operating and the belt driven coolant pump is not circulating. The Espar will overheat until the high temperature cut-off is triggered. By that time the Espar is really hot. Often hot enough to distort some of the plastic covers.

vic

I don't know if my boost heater has ever been run, but I'm trying to get it working now. The panel switch seems to be doing its job, as pins 1,6, and 7 (and I believe 4, if memory serves) are powered when i try and turn it on with the engine running, coolant pump is working, but the heater does nothing. No sign of fuel from the feed line. I've confirmed by powering pins 6 & 7 directly. Also tried disconnecting the battery for a couple of hours. Anything else I can do, or is the next step finding someone who can check and clear codes?

Andy

tinman said:

... Anything else I can do, or is the next step finding someone who can check and clear codes?

Andy

Click to expand...

This may not be what you want to hear, but I would begin by removing the unit to give it a good cleaning and inspection. Most of the components can be tested using a VOM or 9 volt battery. That will give you a base starting point.

Chances are that a good cleaning with verified component operation will get you going without needing any special code resetting.

This thread meanders, but the all the information you need should be there.

https://sprinter-source.com/forums/showthread.php?t=30384

vic

Aqua Puttana said:

This may not be what you want to hear, but I would begin by removing the unit to give it a good cleaning and inspection. Most of the components can be tested using a VOM or 9 volt battery. That will give you a base starting point.

Chances are that a good cleaning with verified component operation will get you going without needing any special code resetting.


vic

Click to expand...

Thanks Vic. You think the need for a cleaning could cause the zero response that I'm seeing?

Andy

tinman said:

Thanks Vic. You think the need for a cleaning could cause the zero response that I'm seeing?

Andy

Click to expand...

Not necessarily just the cleaning alone, but the component inspection and tests might reveal something. vic

Finally tried to get the Espar boost heater to work. Took it out, dismantled, found it pretty clean, burner tube screen intact. fan works, glow plug works, checked the dosing pump and it works. Cleaned it up, reassembled with new gaskets, reinstalled, found power at all the appropriate points on the feed connecter, hooked up, tried to fire it up, NADA. Mine just has the engine-running bowtie switch. Is there anything else I can check, or should I assume the control unit on the heater is shot?