Long Range America Tank error code

Okdisco

Member
Nov 8, 2021
6
2
Tulsa, OK
I had an auxiliary Long Range America tank recently installed. The installer is not a Land Rover mechanic but is the installer recommended by the manufacturer. I feel comfortable that they did a good job and are being honest with me and have so since the start about their Land Rover knowledge.

That said I’m getting a check engine light with a code for a leak. P0442. They have smoke tested the setup and can’t find a leak anywhere. They think that they truck is pulling a vacuum on the fuel tank to check for leaks and throwing the code when it times out as there is much more capacity on the two tanks so the truck does not expect there to be that much time to go by. I’ve filled both tanks up when first installed and the code started right from the get go. We are checking with the manufacturer for answers.

Has anyone here installed/had installed this tank and had this issue?

Anyone have any thoughts on the truck pulling a vacuum on the fuel tank?

TIA, Frank
 

discostew

Well-known member
Sep 14, 2010
6,738
636
Northern Illinois
I think what your mechanic is saying is that when the DMTL pump runs it's test by pumping pressure into the fuel tank it doesn't expect there to be that much volumn of tank space to fill and it times out. Makes sense. The system checks for leaks with a pump. The ECM knows how many amps the pump will draw when the system is sealed up. If it doesn't reach that pressure and or times out before it sees the amperage draw of the pump start to rise it assumes there is a leak. But those pumps are so shitty it pays to start with a new pump.
 
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Okdisco

Member
Nov 8, 2021
6
2
Tulsa, OK
Disco stew, Thank you.

Its also very difficult to fill these tanks. Went into the gas station with both gauges essentially on E. The oem tank would not add fuel unless I held the pump handle and slowly added fuel and the aux tank wasn’t much better. In total I put in 38 gallons. That is a far cry from the 61 they should hold. Would the DMTL pump affect the tank filling? Should I replace the purge valve at the same time. I think there is a purge valve under the hood right?
 

discostew

Well-known member
Sep 14, 2010
6,738
636
Northern Illinois
Disco stew, Thank you.

Its also very difficult to fill these tanks. Went into the gas station with both gauges essentially on E. The oem tank would not add fuel unless I held the pump handle and slowly added fuel and the aux tank wasn’t much better. In total I put in 38 gallons. That is a far cry from the 61 they should hold. Would the DMTL pump affect the tank filling? Should I replace the purge valve at the same time. I think there is a purge valve under the hood right?
Yes the purge valve is under the hood, but probably not the cause of this. It's more lkely related to the DMTL pump. Something might not be venting properly. When the fuel goes in the tank the air from the empty tank and all the vapors in that air is sent to the charcoal canister. If the air can't do that because the vent hose is pinched or more common twisted then the fuel can't enter the tank. So after the vapors get run into the charcoal canister the purge valve pulls that vapor from the canister and burns it.
 
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MM3846

Well-known member
Feb 18, 2014
1,040
75
LI, NY
Disco stew, Thank you.

Its also very difficult to fill these tanks. Went into the gas station with both gauges essentially on E. The oem tank would not add fuel unless I held the pump handle and slowly added fuel and the aux tank wasn’t much better. In total I put in 38 gallons. That is a far cry from the 61 they should hold. Would the DMTL pump affect the tank filling? Should I replace the purge valve at the same time. I think there is a purge valve under the hood right?
Yup. I could barely put gas in my truck over the summer with a bad DMTL pump. Buy the Bosch (not LR branded) one.. it’s like $70.
 
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p m

Administrator
Staff member
Apr 19, 2004
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La Jolla, CA
www.3rj.org
Stewart is right.
The late OBD-2 system checks the operation of the EVAP system and the operation depends on the volume of the fuel tank.
This is one of many hurdles Nick Markiw had to overcome while adapting LS engines to Land Rovers.
Unless you reprogram the system so it would know the combined volume of the fuel tanks, it is likely to throw CEL with the P0442 code frequently.