E53 3.0d 2001 not starting (one more:))
 

Hi Guys and Gals,

After overheating because of a blown water pipe (now replaced) the car doesn't want to fire up. I replaced the battery to be sure.
Dashboard looks like a Christmas tree (see pic attached), starter works, but engine doesn't start.
I also attached the error memory.

My guess is that the thermostat is dead (needle in the red before attempting to start) but replacing it will it fix the starting issue?

Help!

After some digging, while plugging the car to a bmws diagnostic tool, the DME shows up as red meaning that there is no communication with it.
I checked the voltage to both the DME and the TCM and I noticed that the TCM receives 12v while the DME receives 1.46v. Another surprising thing is that when I unplug the relays I can find in the same box (two blue and one brown - the brown is for the wipers apparently), both the TCM and the DME receive the same voltage as said above.

Can someone tell me if the voltage the DME receives (1.46) is normal? which would tell me that the DME is dead.

And by curiosity, why would the DME still receive voltage when the main relay is unplugged?

thanks

Where are you measuring this voltage? It seems low for a supply rail but it may be a signal line... :dunno:

Have you looked at the circuit diagrams to see what the voltage should be? Pin 1 and 8 on X2411 and pin 26 on X2424 should all read 12v.

1 and 8 on X2411 both receive 1.4v
I will check the pin 26 on X2424 which I didn't do yet. Will post there results. thanks

Seems like 1.4v on X2411 pins 1 & 8 will be a problem - should be at least 12v (or whatever you system is at).

Fuse #1 (30A) in the engine box fuse holder must be blown.

Check out this diagram..

https://www.newtis.info/tisv2/a/en/e...ronics/wMfEKWd

I ran some new tests and changed the main relay to the DME (assuming this relay I bought new from the bmw shop works fine).
- on X2411, pins 1 and 8 now receive 0 volts
- The main relay still receives its 12v
- The fuse #1 30A you are talking about in the box A8680 is fine as well as the 5 others. I noticed that all the fuses receive 0 volt (checked the main cable plugged to this box as well).
box A8680

My understanding is that the electricity flows to the relay (this is fine), then to the fuse #1 30A, then to the DME connector. I am not familiar with TIS yet, but do you think this is correct? I am wondering what else could cause the electricity not reaching the DME.

Looks like the DDE (it's not a DME) controls the main relay (K2003) itself, via pin 9 on X2411. This diagram shows it pretty well.

https://www.newtis.info/tisv2/a/en/e...-relay/vda2nTu

Several things may prevent the DDE from closing K2003 - the immobiliser, a fault etc.

Might pay to check the rest of the other fuses first though: -

F31 (behind the glove box)
F47 (fuel pump fuse - behind glove box)
F47 (fuel pump relay fuse - behind glove box)

There are a couple more diagrams that add more details: -

https://www.newtis.info/tisv2/a/en/e...dde4-0/vrZMIEM

https://www.newtis.info/tisv2/a/en/e...dde4-0/w0LzxMn

HTH...

It sure helps thanks. I had little time to spend on this today but checked them and they are working fine.

I would be happy if this is the immobilizer and not the DDE (DDE costs 2.5k at the dealer and the car is only worth a little more than twice that). How do we know if this is the immobilizer?

I have been thinking about opening the relay K2003 and forcing it to close while plugged, hopping that it would or make it work or at least allow me to connect to the DDE via OBD. Not sure if this is a risky procedure.

Not sure I would want to pull the relay apart - easier to remove it and jump the correct pins on the socket.

Something is stopping the DDE - need to figure that out. Does the temp gauge fall to zero when you turn off the ignition? And when you turn on the ignition, it climbs right up to full? Have a closer look at the temp sensors etc. as it may be this false temp reading that is causing the DDE to lock out the engine....

Yes the temp gauge falls once I turn off ignition / climbs to full when ignition on.

Changing the sensor was on my list before I have been told by a bmws mechanic that it should not prevent the engine from starting. I changed the thermostat/not the sensor.

Thing is, a bad sensor should not (in my opinion) prevent the computer from accessing the DDE. In my case DDE cannot be accessed via OBD anymore. And as we found above, it does not receive 12v making me believe that DDE is not dead.

Agreed - something is shutting down the DDE relay and it DOES seem that the DDE has no power - either as a result of the main DDE relay being "off" or a wider lack of power to the DDE.

As the DDE gets power from multiple locations (for different aspects of it's operation) you may have to check them all.

From this diagram, I can only see two "direct" power feeds - pins 1 & 8 on X2411 from fuse F1 in the ECU box and another via pin 26 on X2414 from fuse F31 in glove box. But as the feeds on pin 1 & 8 on X2411 are ultimately via the DDE relay (which we know is off, controlled by pin 9 on X2411) there may be other power feeds hidden on the diagram - it will require some time on the newtis web site looking at the DDE functions for other possible power supply sources to check.

I will try bypassing the relay but I just read this as well much might change the whole thing
DDE supply
So we are not looking at the proper power supply. And based on this below, I believe that the sensor could be the cause.
Coolant sensor
I would like to unplug the sensor or the fuse that goes from the sensor to the DDE if any but I cannot find it.

Ok, so the main relay does close (I opened it to see) and the power supply doesn't come from X2411. I also checked all the pins of the other connectors and the 2 biggest ones (58 pin connector and 40 pin connector) have pins providing 12v, sometimes less. The pins from X2411 sends about 1.4/1.5v which I believe is normal since they are not the main power supply.

Next I would like to disconnect this coolant sensor to see if it impacts (if I find how it is connected to the DDE) or leave it to the garage.. :S

I went to tool32 to check if the DDE is dead but some commands are still responding. It cannot access to errors though. And the VIN is still there as well. Hopefuly it talks to someone here.

The TIS you reference states the sensor is on the cylinder head, so that narrows it down somewhat.

B2232 perhaps - https://www.newtis.info/tisv2/a/en/e...sensor/UOcU68k