BMW E46 330D 2005 intermittent starting fault code 4302

[jonbell]

Hi Everyone,

Just joined and hope for some advice on an issue I am having. I have a 2005 E46 330D Touring (Auto), she has done 60K and is my pride and joy!! She is though, proving to be a right royal pain in the backside!

Story so far:

I have had intermittent starting which doesn’t seem to have any particular routine to it. The engine will crank but does not fire up. I stuck my scanner on and picked up a constant code I cannot seem to get rid of and a few other codes (glow plugs!) when I am having the issue, but not when she does decides to run!

I get fault code 4302 constantly whether she fires up or not.

I get fault code 4B90 when she doesn’t want to start.

 

Now, lots done so far.

1.      Fuel tank pump replaced

2.      Fuel filter under passenger seat replaced

3.      Fuel pump under passenger seat replaced

4.      Fuel pump relay replaced

5.      Fuses in the ECU compartment checked and ok

6.      Fuel quantity regulator on the back of the HPFP replaced twice with genuine Bosche#

7.      DME replaced

Now, I know the fault codes have specific nuances for each car brand. I am not sure exactrly what 4302 means in my car and I also assume that 4B90 is perhaps a result of the 4302 code?

Reading live data, I get about 2-4 bar with the ignition turned on and the electric pumps running. When she doesn’t want to fire up this goes to a pathetic 6 bar when cranking. When she does fire up, it will go to 400 bar and sit there quite happily on tick over, with a 3 bar fluctuation now and then.

I can only think that there is something wrong with the fuel rail pressure sensor or rail pressure regulator or HPFP?

Also, does anyone know where the “earth bar” for the engine sensors is?

I want my car back!!

Thanks

Jon

[Greydog]

Morning Jon

Sounds like you have chased this around for awhile, have you checked the Throttle body and Throttle position sensor and loom ? 

Also check carefully the loom on the engine I have seen an issue caused by cracked insulation causing an intermittent short to earth. 

I guess you are aware of www.realoem.com Check the engine earth strap and it's connections engine mount to chassis rail seen a couple that needed replacing. Also in the engine bay there are 2 or 3 from memory earth multi-points worth checking they are clean and remount using an electrical contact paste.

Last not sure what Diagnostic your using But PA Soft BMW 1.4.0 is perfect for your car just need a Laptop to set it up it will give Dealer level access 

Good Luck

Dave

 

[jonbell]

Hi Dave,

Thanks for all of that, very very helpful. I will be on it asap. Particularly the earths. Will check throttle body but I would have hoped it would have thrown a code or two at me if not functioning? When it does start, seems to run fine. Had another look this morning at the live data. Only 2 bar with ignition on. This did use to be 4 bar but I have just replaced all of the pumps and filters?? Cranking gives me about 20 bar??  Will come back once done.

Thanks again

Jon