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Discussion Starter #1
If you are having trouble working on the G&K installed EVAP system this might help you in finding the problems.
The Black Box is sold by G&K (about $500.00) and the purpose of the box is to run self test on the EVAP system and give you generic codes when there is a problem. It checks the tank by closing the Tank Vent Solenoid and opens the Purge Valve and let’s vacuum in the fuel tank. The Pressure Switch measures the pressure and sees if there is a leak after it holds it for a certain amount of time. If it detects a leak, it sets a code. An example is P0456 Leak. The Black Box can only be accessed by a generic OBD-2 code reader and not by the Mercedes STAR DAS system. The Black Box is located behind the left plastic panel in the trunk compartment.
The line Purge Valve is made by smart (P/N Q0010601V003000000 about $39.00) and has a resistance of 26 ohms. There are two wires going to it one is green and the other is orange. The green wire is grounded to the frame and the orange wire goes to the Black Box.
The Tank Vent Solenoid is made by Ford (P/N F753-9F945-C8, about $95.00) and has a resistance of 59 ohms. There are two wires going to it, one is gray and the other is brown. The gray wire goes to the Black Box and the brown is grounded to the frame. This valve is normal open until it is commanded to close by the Black Box.
The Pressure Switch is made by Bosch and used on Porches (P/N D261-230-015 about $95.00). It has three wires going to it. There is a yellow, black and blue wire and they all go to the Black Box. One wire will be a 5 volt reference, one is a ground and the other will be the return voltage.
The Carbon Canister is made by Ford and used on Rangers (P/N F65X-90653-AA about $60.00) and is used to store fuel vapors until the Black Box commands it to pull the vapors into the engine.
The Bleed Canister is made by Ford (P/N 3S4U-9G723-C) and is used when the vent valve is opened to filter the air. The canister is located next to the intercooler, behind the air filter box.
If you are looking for a pressure leak because of a code, the easiest way to check for leaks is to use a smoke machine. Look around the top of the tank around the tank vent part that was added by G&K and the fuel pump/sending unit o ring. Also look at the hoses going to the top of the tank. Remember the Tank Vent Solenoid will leak like crazy until it is commanded to close or you send power to it to close it.
Some problems I have seen are the wires being broken or chewed on by mice. If you see a Pressure Sensor code saying it is bad more likely it is the Black Box is bad. If you cannot access the codes or the ECU (MEG) the Black Box may be bad because of the circuit board being broken. Open up the Black Box and see if the circuit board has fallen off because of too many bumps in the road. There is also fuse on the Black Box wiring harness make sure it is not blown. The G&K cars uses a Mercedes gas cap and not the original smart cap. Of course if you leave the gas cap off, it will give you a large leak and code. If the Bleed Canister filter gets stopped up it can give you problems. If you are rechecking for codes after you fixed the problem, you may have to drive it and shut down the engine at least three times for the Black Box to run the self test. Check for pending codes. If you access the ECU for codes using the Mercedes STAR DAS System sometimes you will see a purge valve trouble code telling you it is bad, most of the time it is OK.
If you want to put it back to the way smart designed it to be, it is easy to do. You will not have a check engine light problem anymore. But legally it would be for off road use only.
 

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Leroy, you're my hero. Again.

The bleed canister, is that the part that goes into the top of the gas tank on the passenger side towards the front of the car? Thats where my fuel tank leak is as the "sealant" G&K used around that area isn't sealing.
 

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Discussion Starter #3
The bleed canister is right behind the air filter/ ECM box bolted to the fire wall. You cannot see it from the engine compartment. You have to look through the tire well.
There is no sealant that works with the PE/High density fuel tank. Even epoxy will just peal off. As long as the tank is not broken you can try installing a gasket under the fuel vent on top of the tank or just by pass it altogether and plug it.

Leroy
 

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thank you for great info. I would like to know how to by pass this system. Someone said that all I had to do was to put the white wire and the white wire with blue stripe together and the black would be bypassed. Is this correct?
Dave
 

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Blck box issues

My vent valve is bad but Mercedes discontinued it..... what should be my next step into replacing the part, instead of buying the 500 dollar box.
 
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