connectors removed

 

It means there is a path somewhere back in the electronics. I do not think it has any bearing on what you are looking for.

 

OK. Now do it on the ICM back.

 

Go it, will ignore the pin 16 to ground finding.

 

with plugs attached but battery disconnected.
IP6-20 to IP6-3 = 5.759k ohms
IP6-20 to IP5-4 = 172.7 ohms
IP6-20 to IP5-3 = 202.2 ohms
IP6-10 to IP6-3 = 124.0 k ohms
IP6-10 to IP5-4 =41.96 k ohms
IP6-10 to IP5-3 = 41.90 k ohms

 

The 12.39 definitely indicates a short to B+. Since there is no current draw it means the short value could be most any value.
It may be of value at this point to connect everything back up and then disconnect IP2. DONE

This will leave only the ICM and Audio unit on the SCP bus. Do the 2 DLC checks again.
2 - 16 = 12.46 Volts
2 - 5 = 282.5 ohms

If the voltage is still over 12v disconnect the audio CC8 and check voltage again.
Removed the audio unit months ago. Plugs are disconnected and laying lose in the dash.

If still over 12v we are back to the ICM most likely having an internal short.
still over volts… battery voltage.

With the battery disconnected what is the value of the termination resistors?
ok
2-5 DLC - 357.0 ohms
There are supposed to be a number of termination resistors, in the SCP circuit, however the documentation does not give individual values or where they are located.
So there is no way of knowing where the resisters are located? With the plug IP2 isolation of the the rest of the modules, I would expect that only one likely resister is inside of the ICM… possibly two if the computer is involved as well?

I would expect a value of 120 if there is only one and it is in the ICM. If there are two then you would get 240 or three would be 360 Ohms.
The value 357 ohms.

 

Need to identify and test the termination resistor in the ICM next.
A wiring diagram of he ICM would be very helpful.
Still have too much current and I don’t know how to trace it to the source without a comprehensive wiring diagram. At this point all I can do is put eyes on everything.

 

You have just checked the termination resistor in the ICM - 357 Ohms - which is about right if if we assume there are three termination resistors overall.
With no connectors on the IPM what are the Ohm resistance values, on the back of the IPM, of:
IP6-10 to IP6-2 =
IP6-20 to IP6-2 =

"This will leave only the ICM and Audio unit on the SCP bus. Do the 2 DLC checks again.
2 - 16 = 12.46 Volts You are getting this since 16 is B+ and the voltage is being read across the 282.5 Ohms to ground.
2 - 5 = 282.5 ohms" In theory this should be very high if not infinite resistance. I do not have the internal schematics to verify any of this!
What current are you referencing here: "Still have too much current and I don’t know how to trace it"

 

IP6-10 to IP6-2 = ( there appears to be next to no reading)
IP6-20 to IP6-2 = ( same here)

 

What does 'next to no reading' mean? Is it zero or infinite?

 

Apologies, the meter indicates no continuity.

 

That is good. It means your ICM is probably not the issue. We need to trace down the 282.5 partial short to ground that you found in the cable.

 

So I need to trace pin 2 on the DLC back to its source? Any thoughts on best way to accomplish this with some sort of a scientific method? Noting of course that the other modules are isolated from the bus by disconnecting IP2 connector, you would think that this would simplify the number of incursion points for a short.

 

You indicated the audio was disconnected from the system in the trunk. Is it also disconnected at the CC10 connector up at the centre console?

 

there is no audio system in the trunk. It did not deliver with the upgraded audio or navigation system. I am referring to the CC10 connection. The audio/climate control is completely removed pending a replacement of an android control system, to be installed later.

 

With all connectors still and battery disconnected, check resistance from IP39-10 to IP39-4 and IP39-5. Do the same for IP39-2.

 

no battery, all plugs reconnected accept for the DSM which is currently in my living room attached to the drivers seat.
2-5=114.9
2-4=114.2
10-4=38.35k ohms it climbs slowly but appears to level off after 2-3 mins
10-5= 38.34k ohms

 

So I have eyes on all of the ground points both inside and out. Every point has been pulled cleaned to bright aluminum and replaced. So it is safe to say that the ground points themselves are not the issue. However the ground points did play a role in the problem as the ohms have reduced dramatically on DLC 2-16 from over 380+ to 115.~. It is supposed to be 120ohms. So that moved in the corrected direction. Still have a short to battery somewhere. So as I needed to clean the carpet anyway…. I pulled the interior out.



All the wiring looks OEM and in excellent condition. Now that I have easy access to the under dash I am going to spend some time and effort looking for bad wiring and for corrosion on the plug connection pins again. May pull the cabin fuse block to be sure nothing is amiss. If I have to, I will pull the entire dash out of the vehicle… this car is not going to beat me!

 

Did you try another SDD scanner? Once my clonned mongoose semi-died that resulted in unstable connection and no communocation to SCP. It could be make alive for a while by pushing side while in the socket. We dug all SCP network without results. All the rest networks were answering Ok. My indy repaired it by soldering a jumper inside from board to the socket leg.

 

Interesting idea and one that may be worth pursuing as the mongoose adapter I purchase is aftermarket, however, we know by the tests suggested above that the SCP bus has a short to + because of the incorrect voltage reading of 12+ when it should be 3volts or less when testing DLC 2 & 16 pins. So as I understand the issue; until the short is resolved, the SDD testing for the SCP BUS is really going to be moot issue as there would be no way to read anything because of the over volts.