E70 3.0sd multipe errors, reduced power

[ard]

I think I may be looking at that one diagrm too symplistically.... note that the differnt sensors are shows as 'dotted boxes' on this diagram: https://www.newtis.info/tisv2/a/en/e...200806/p6BEsjg

I think this is more of a diagram showing functioanlly ho power is distributed.


But to see the actual WIRING, you need to drill into each sub-system...


Now look at each of these:


https://www.newtis.info/tisv2/a/en/e...lation/cuMAnjp


https://www.newtis.info/tisv2/a/en/e...supply/d2DNgSR


https://www.newtis.info/tisv2/a/en/e...system/ctbuNFK


https://www.newtis.info/tisv2/a/en/e...-flaps/cmWlMr3


Just a few, didnt list all. You can see that the power supply from F02 isnt a simple 'red wire to the module'....

[mxxxs]

I think that all the power lines connect to pin nr4 on the fuse box, one of the 2 pins of the fuse. So, i will check later for a short circuit between pin 4 and ground. I believe I am going to find a short circuit there, but still I will not know which valve/sensor is faulty. There must be a "junction box" somewhere, that all the power lines meet, but I can't find it.

[ard]

I'll qualify this to say all of my comments are based on looking at the schematics...


Pin 4 of connector X8582 seems distinctly separate from connection point X2377


I am going to guess that X23778 may in fact be inside a wrapped bundle of wires. Consider unwrapping the bundle to try and see if something is hidden.



ALSO!! you may not find a solid short just ohm-ing things. There MAY be a circuit that isnt ';active' until the car is powered on, but once powered on the circuit closes and then a bad sensor/.actuator causes the short/fuse blow. Odd but possible. Look at this:


https://www.newtis.info/tisv2/a/en/e...lation/cuMAnjp


See the 20A supply from F02 goes to the pre-heater in the o2 sensor. The DME actually 'controls' this by grounding the other end of it at pin 3. When the car is off, pin3 is not grounded- it is only when the DME is on and decides to run the preheat that it grounds that line. At which point the pre-heater then pulls current through F02. if that o2 is bad it would then pop the fuse. My point is that static checking might be confusing at first (hence I posted all the little 'sub-diagrams' above)|



GL!

[Clavurion]

Connector X2377 is a hub cap connector inside that wire bundle. So unwrap the tape and locate the wire bundle with a rubber cap. There should be 7 red/yellow and one violet wire on the same cap.

https://www.newtis.info/tisv2/a/en/e...200806/p6BEsjg

[Clavurion]

Originally Posted by ard

ALSO!! you may not find a solid short just ohm-ing things. There MAY be a circuit that isnt ';active' until the car is powered on, but once powered on the circuit closes and then a bad sensor/.actuator causes the short/fuse blow. Odd but possible. Look at this:

https://www.newtis.info/tisv2/a/en/e...lation/cuMAnjp

See the 20A supply from F02 goes to the pre-heater in the o2 sensor. The DME actually 'controls' this by grounding the other end of it at pin 3. When the car is off, pin3 is not grounded- it is only when the DME is on and decides to run the preheat that it grounds that line. At which point the pre-heater then pulls current through F02. if that o2 is bad it would then pop the fuse. My point is that static checking might be confusing at first (hence I posted all the little 'sub-diagrams' above)|

In this case we are measuring resistance of the voltage supply lines (from F02) against solid ground point (resistance of the supply wire and end device). So it won't matter (for the measured resistance) what the vehicle does on the ground side when it's activated.

[ard]

Originally Posted by Clavurion

Connector X2377 is a hub cap connector inside that wire bundle. So unwrap the tape and locate the wire bundle with a rubber cap. There should be 7 red/yellow and one violet wire on the same cap.

https://www.newtis.info/tisv2/a/en/e...200806/p6BEsjg

Thanks for explicitly stating this. very helpful