Quick brief: I'm doing sales work over here at a car shop in Houston, TX, but I tend to help on repairs because I'm the only computer savvy person. A customer brought this car in for repairs, and i'm trying to locate the problem.

When I got the car it was not starting, except for once in a while. You could crank it for a whole day and it would'nt fire up, then suddenly as if nothing was ever wrong, it would start and be fine. When it cranks, it actually sounds like it turns on, then suddenly shuts off as if something is telling it to turn off. It has started and ran fine about 3 or 4 times out of the 100+ cranks.

When we got the car I checked the spark plugs, they were fouled but sparking, so i cleaned them and put them back in. I checked the fuel pump for a leak or corroded wires but everything looked good. We had the crankshaft position sensor replaced, still no start.

I'm thinking this must be a sensor somewhere but the only codes i'm getting are as follows.
P20D4 P1999 The load limit is active. (P1999)
P202E P0120 [8] M16/6 (Throttle valve actuator): : Deflection of throttle valve (P0120)

Since I knew we were getting spark, we tested to make sure we were getting fuel, so we hooked the fuel line to an external machine which would pump gas into the engine itself. The car still wouldn't start up with this setup, but suprisingly the car would stay running if fuel was sprayed into the intake manifold. I have a feeling the pump on the car works, and so does our setup, but something is shutting down ONLY the fuel into the engine.

Important to note, I had removed the fuel pump and noticed there was no gas in the car, but the gauges read out that the tank was half full. All the other tests were perfomed with gas in the vehicle.

I know these cars have issues with fuel pumps and CPS's, but this one is just really strange. The keyless start does work and no 'battery dying' messages have been reported. I just don't know where to go with this. I've searched for the fuel pump relay but haven't found it, all Mercedes could tell me is the part number and K27/1 or K27/2. I'm really at odds on this one.

If anyone could help with any sort of information, direction, or inspiration, I would truly appreciate it.

 

So, the car seems to have power all the time, but won't turn over, correct?

When you turn the key, the starter gives a chug, so you know that it's working?

I would bet money that one of the 2 fuel pumps is either not working or the line at the top has come unplugged & there is no pressure.

This happened to me twice (after the fuel pump recall was completed) before it was fixed properly. I did not enjoy watching my car on a tow truck either time.

 

The car does in fact turn over, but right before it starts, it seems like something is shutting it down. The connection on the fuel pump is intact, and they do appear to be working. Even with the external fuel pump rigged up, the system does the same thing. We just had a technician come in to look at it, and he noticed the throttle valve wasn't moving enough. He will attempt to program the car to relearn the throttle positions, and i'll let you know what happens.

 

You know that there are 2 separate fuel pumps under the rear seat, right?

One under driver's side, one under Passenger side.

What you are describing is exactly what happened to me. The car seems like it wants to start, but just won't.

 

I did notice the second, and I want to think they are bad, but its quite hard to tell. I checked the pressure at the test nozzle on the engine and it reads 70psi which I think is pretty good. But then again, the fuel sender unit (which is part of the pump) that gives the read out for the gauges is messed up. Still waiting on word for the throttle actuator. Thanks for all the help

 

tested the throttle valve against another e55, still the same problem. although another code popped up. P2042 Safety fuel shutoff detected. hmm..

 

Check your CRANK SHAFT SENSOR.

 

replaced the cps, still nothing... does that even throw a code when it goes bad? does anyone know about the key's built in security system? can that go bad to the point where the car recognizes the key but won't allow the car to start? also, does anyone know where exactly the fuel pump relay is?

thanks again!!!!

 

Okay, I think i've narrowed it down. Out of the 100+ codes this car is throwing because of a dying battery, one stands out. The key for the car is in 'transport' mode.. anyone ever heard of that? grrr...

 

Bringing this thread back from the dead.

After 2 days of scouring the forums (various ones) the OP describes close to the same problem I am having.

Background: Also an 04 E55. 79k mi. regularly serviced, etc. (next service [B] in 45xx mi), previously-CPO till 100k, till previous owner sold it to dealer, from whom I purchased it from.

Story:
The car was sitting at the local car wash as I was drying it off from giving it a quick spray. The motor was on and idling normally, water temp nominal, everything fine. Although, two malfunctions had popped up a few days before.

1. Emissions inspection performed on time?
2. Main inspection performed on time?

Don't know how these are malfunctions, but anyway, after I finished drying, the car had shut down without my knowledge as I was talking to a friend away from the car. As I go to leave, I find the car had shut off, key still in the "on" position. I go to restart the car, nothing. Let the car cool down as I know the CPS likes to fail during warm conditions even though it was freezing outside. Fully cooled down it still would not start. End up towing it home as I had nothing to work with and it was 1am and 30° outside...

After 6 months of owning the vehicle (and driving it regularly) this is the first problem I've had and it may potentially be a major one. fml...

As with the OP, the car wants to turn over, but it just won't.
- Replaced the Crank Position Sensor (CPS) last night, but to no avail.
- Did a soft ecu reset, nothing.
- Reset via unplugging the battery cables, touching them together, and waiting 15 mins, plugged it back up, still nothing.
- Checked for Spark - CHECK
- Checked for fuel at the bleeder valve next to the s/c - no pressure during the crank cycles. (the fuel barely trickled out.)
- The fuel gauge read over a quarter tank. Went to the gas station, filled up a gas tank, went back to the house, and filled her up. Gauge reads half a tank now, so the fuel level sensor isn't faulty...
- Poured a bit of fuel into the throttle body and the motor fires right up. Ran for a good few seconds on a eighth of a Dixie cup of fuel. lol
- The fuel pumps sound as if they are priming when the ignition is turned to the "on" position.

Going to check/recheck today:
- Pull the back seat out and check if both pumps are priming and check the lines as I know there was recall...that may or may not have been performed (have to check my VMI)
- Also going to check the fuel pump relay in the trunk
- Fuel Lines
- See if I can pull some codes, though there is no CEL...
- And this -> https://mbworld.org/forums/4152149-post10.html

I'll report back the findings as soon as I'm able to.

Also, if they're ANYONE that can shed ANY light on this situation...it would be greatly appreciated...

Thanks,

Mike

 

seems like you have a fuel delivery issue.

 

Crank shaft sensor
Fuel pump relays
Fuel pumps
Weak battery

Common causes..

 

My personal mechanic hasn't been able to perform many checks as stated due to this crazy snow and crappy weather (TN); however he was able to check but was not able to locate the supposed secondary fuel filter thing as described in the permalink in my previous post.

If anybody does know the location; moreover, the existance of the (a) secondary fuel filter on the w211 e55s, could you possibly post a picture and a brief description of how to locate it? Thank you.

Also i am aware that there are two fuel pumps with built in primary filters, which will be checked as soon as this weather stops being ****ty. Lol.

Will update once more information has been attained.

Thanks all for the info,

mike

 

Please if there's any update i will be thankful, am experiencing something VERY similar on a CL55 2003
Thanks
Jad

 

I have the similar experience. Check if your fuel pump is getting electricity.
Finally I have to change the fuse socket at the trunk next to the battery cus it was melted.

 

Sorry to update so late guys. Turned out to be the raised plastic outlet piece on the secondary fuel pump (that sends to primary pump / scavenges) where the c-clip rests to hold the fuel line to the secondary fuel pump has a minuscule crack in it thus the c-clip could not fully seat and the fuel line popped off under pressure. The fuel line is now held on to the fuel pump outlet with the c-clip and the assistance of fuel resistant zip ties .

Also a bit more information for the web and others to use. Turns out during our trouble shooting, we found that the secondary fuel pump(s) which scavenges fuel to the other side of the tank over the drive shaft tunnel / sends fuel to the primary pump (which sends to engine) will not prime if it isn't able to send any fuel, naturally; moreover, the primary pump will not fully operate if the secondary pump(s) do not prime the primary. The primary pump will prime without the secondaries, but it is not enough to fire the motor.

We figured it was the primary pump ****ting on itself; however, it wasn't. I am at a loss so if ANYONE needs a PRIMARY FUEL PUMP for W211 E55 AMG and i believe CLS 55 AMG (be sure to check your sources to verify), I have a brand new one (that's been sitting on my desk for like 5 months. lol) $350 SHIPPED anywhere in the continental US. I have no use for it, and would rather sell to a help a member out than return it and pay 20% restocking fees.

Contact me at michaeloconnor8807@gmail.com

This e-mail is linked directly to my phone.

 

Pic of the BNIB fuel pump. The yellow on the hoses is NOT fuel discoloring. It's oem markings.

Remember this the PRIMARY fuel pump located under the DRIVER SIDE REAR SEAT. The secondaries are under the passenger side rear seat.

 

Installing yourself? Make and post a DIY while your at it

 

Updating this thread to give more information on the fuel filter / sender I have.

Mercedes Part # A211 470 49 54

I'll be creating a FS thread as well.