Heater Booster Trouble Shooting Question

rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
2006 Sprinter with Heater Booster (HB) that has not worked since I purchased the rig with 64K miles. No 7 Day Timer. Coolant Pump works fine with REST button. I tried the suggestions mentioned on the forum, including pulling fuses 1 and 6 with engine running and HB button on, but HB never fired. Pulled the HB and removed cover over the fan. Fan moves but is crunchy sounding. Cleaned around fan base and housing and now sounds better, but is still slightly crunchy. Placed HB on bench and connected 12VDC battery to pins 1(+) and 2(-) on HB harness. Then 12VDC to pin 6 to enable HB. Fan never moved, but should for 2 to 3 seconds during pre-start check per my forum reading. Is it correct to assume the HB ECU is dead or is there something else I need to do to power the HB ECU? :hmmm: :idunno:

Removed ECU and checked resistance:
---------------------------------------------
66.2 ohms Fan Motor
0.6 ohms Glow Plug
12.06K ohms Overheat Sensor @70F
11.56K ohms Temperature Sensor @70F
0.8 ohms Flame Sensor
I believe all readings are reasonable?

Thanks,
Patrick
 

autostaretx

Erratic Member
If memory serves, the Espar's internal controller will go into lock-down mode if it has ten (i think) failed starts in a row.
Clearing that mode requires a "dealer level" scanner.

--dick
 

Patrick of M

2005 T1N 2500 (NA spec)
If you have a timer controller you can run a wire from the Espar to the timer and you will have diagnostic and code clearing abilities (lock down etc.). There are threads in the forum on it....try “Espar programable timer diagnostic”. The instructions are rather meticulous , I just spliced in a wire and ran it to the Espar through the firewall.
Re the fan, lube/clean it more, the wee electrical motor will fail if it is crunchy, it should spin very fast. I used Spray silicone lube to clear the fan without making everything greasy.
 

vanski

If it’s winter, I’m probably skiing..
I'd suggest testing the fan via a 9v battery to the pins that only lead to the fan. I forget which pins they are but it’s obvious when looking at the harness inside the hb. If it spins up but you’re getting blower motor short to ground code you most likely need a new hb control unit.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
You may need a new (used?) ECU in the Espar... but I’d scan it first to confirm. Mine had a fault in the coolant temp sensor that made it look hot so the furnace simply chose not to fire up.

The AP200 will talk to the Espar, both the boost “HBM” and aux cabin “CHM” models (they’re on the same K-Line to obdii pin 15 but have different node addresses). The AP200 has some live data, but it can’t send test commands to the heater like the native Eberspacher tools can (they can run the fan, glow plug, and fuel pump...). It WILL read and clear fault codes, and bring the ecu out of locked/disabled mode, which makes it a bargain at $70. BUT, be aware the AP200 requires a smart phone with a data connection on so it can validate your “Benz-Sprinter” App license, and the app is BIG, and since iOS often drops it into the cloud restoring it could cost you $$$ in data charges. So if you’re often off grid, a self-contained unit like the MD-808 (double check that it speaks Espar?) may be a better choice, but that’s a few hundred dollars more.

(I have no immediate plans for an Espar version of the Nautabox, though much of the software interface is cracked and the software included on the SD card sent with the current v2, but I didn’t implement it on the Arduino due to space constraints - running a third k-line uses more ram, and the AP200 filled that niche. We also didn’t record a “clear codes” command sequence so I don’t yet know what that looks like on the Espar at this time. The IC/ATC/HBM/CHM all share the same Pin-15 in the OBDII socket, so adding that channel to the box remains a long term goal)

-dave
 
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rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
If you have a timer controller you can run a wire from the Espar to the timer and you will have diagnostic and code clearing abilities (lock down etc.). There are threads in the forum on it....try “Espar programable timer diagnostic”. The instructions are rather meticulous , I just spliced in a wire and ran it to the Espar through the firewall.
Re the fan, lube/clean it more, the wee electrical motor will fail if it is crunchy, it should spin very fast. I used Spray silicone lube to clear the fan without making everything greasy.
Don't have a the programmable timer diagnostic, but I may need to get one.
I'll try cleaning the fan again with silicone lube - :thanx:
 

rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
I'd suggest testing the fan via a 9v battery to the pins that only lead to the fan. I forget which pins they are but it’s obvious when looking at the harness inside the hb. If it spins up but you’re getting blower motor short to ground code you most likely need a new hb control unit.
I did use a 9v battery on the fan and it did spin up. I have no way to read codes at this time. I guess a programmable timer diagnostic or AP200 is in my future. :cry:
 

markxengineering

Active member
Another good option is the MB STAR C3 tool. Buy on AliExpress with laptop included to simplify things. This is pretty much the ultimate scan tool for the T1N and includes full communication and troubleshooting for the Espar. More than likely, you will reset the ECU and it will work fine, but there's also a chance that the ECU has fried from overheating. The symptom on mine was no fan output or intermittent fan output. Fixed by buying a complete new unit, but I THINK this is the right ECU https://heaters4you.com/eberspacher-hydronic-4-5-parts/542-control-unit-12v-225201043002.html for a little less $
 

rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
You may need a new (used?) ECU in the Espar... but I’d scan it first to confirm. Mine had a fault in the coolant temp sensor that made it look hot so the furnace simply chose not to fire up.

The AP200 will talk to the Espar, both the boost “HBM” and aux cabin “CHM” models (they’re on the same K-Line to obdii pin 15 but have different node addresses). The AP200 has some live data, but it can’t send test commands to the heater like the native Eberspacher tools can (they can run the fan, glow plug, and fuel pump...). It WILL read and clear fault codes, and bring the ecu out of locked/disabled mode, which makes it a bargain at $70. BUT, be aware the AP200 requires a smart phone with a data connection on so it can validate your “Benz-Sprinter” App license, and the app is BIG, and since iOS often drops it into the cloud restoring it could cost you $$$ in data charges. So if you’re often off grid, a self-contained unit like the MD-808 (double check that it speaks Espar?) may be a better choice, but that’s a few hundred dollars more.

-dave
I have an MD808 and l tested/looked for Heater Booster data once previously, but found none. I did, however, not try all the different options for running the the test - Dodge, Mexico, etc. I only tried the European --> Benz-Sprinter. But the two attached Autel files don't show HBM or CHM as available for Sprinters. :thumbdown:
I'll try the tests again anyway - can't hurt. Thanks Dave!
 

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rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
Another good option is the MB STAR C3 tool. Buy on AliExpress with laptop included to simplify things. This is pretty much the ultimate scan tool for the T1N and includes full communication and troubleshooting for the Espar. More than likely, you will reset the ECU and it will work fine, but there's also a chance that the ECU has fried from overheating. The symptom on mine was no fan output or intermittent fan output. Fixed by buying a complete new unit, but I THINK this is the right ECU https://heaters4you.com/eberspacher-hydronic-4-5-parts/542-control-unit-12v-225201043002.html for a little less $
Probably should have bought an MB Star tool :drool: instead of my MD808. Good old hindsight!

Thank you for the link to the ECU! :cheers:
 

Nautamaran

2004 140” HRC 2500 (Crewed)
MBH/CHM are the Mopar names for the modules... MB (and AP200) calls them ZUH (boost) and ??? (aux cabin)

Longshot, but I wonder if the ZHE selection on the 2002-2005 VANEO would connect?

-dave
 
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rv-sprinter

07 Winn View 23J - 06 T1N (NAFTA)
MBH/CHM are the Mopar names for the modules... MB (and AP200) calls them ZUH (boost) and ??? (aux cabin)

Longshot, but I wonder if the ZHE selection on the 2002-2005 VANEO would connect?

-dave
ZHE is the Aux Heater. But it can’t hurt to try the Vaneo selection. Thks
 

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