Old Nov 12, 2024 | 11:38 PM
  #17 (permalink)  
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srt6exy
Joined: Feb 2018
Posts: 27
Likes: 2
From: missouri
Default Re: Need Help, RCM, SLA, TCU? Where to start?

Originally Posted by red_2005_convertible
Hi Srt6exy,
I think you are getting close. Did you back probe these connectors, or were they disconnected while you probed them? Like your first line PCM C4 P1 to TCM L, were both connectors disconnected, or only the TCM? If just the TCM connector was unplugged, and all others plugged in, you should read ~60 ohms. Have you tried measuring the resistance between PCM C4 p1 and p11 into the PCM module (the C4 connector disconnected from the PCM, and just touching the pins coming out of the PCM) or SKREEM P1 and P2 with the connector disconnected and into the module. Assuming that your PCM connector is connected, TCM and SKREEM connectors are disconnected, it looks like you have an open between the SKREEM and the PCM on the CAN BUS. Your reading from PCM C4 P1 to TCM H (8 ohms) looks a little high since this should be a straight shot along one wire like PCM C4 P11 to TCM L (1 ohm) => you might have a damaged wire between PCM C4 P1 to TCM H maybe as S123. And your measurement from SK P2 to TCM L suggests the issue is on the side of splice S123 going towards the PCM. To confirm my guesses, print a copy of the CAN BUS wiring diagram in my post, and write the resistances you measured on the different legs connecting the different pins. The 11kohms is the isolation resistance between pins on the other modules. I also see now that I should've posted what the nominal values were after I fixed my issue so it would be easier to identify the problem. If it really is damage on the wire between S123 and the PCM, that should be fairly easy to fix by running a twisted pair between the PCM and the CAB.
Good Luck
-Jerry

PS. Finding the splice in the engine compartment can be a bear, but I think S123 is on the top of the firewall, under the cowl, midway between the PCM and CAB, or it could be in the fuse box.
Battery Cable off for everything.
When I was measuring things between the PCM and TCM both were unplugged and I was measuring at the front of the plugs themselves. The SKREEM was still plugged in at that time.

After that I started taking apart the dash to get to the SKREEM so the measurements between the SKREEM and TCM were both unplugged as well as the PCM still being unplugged.

I did also try measuring the PCM while plugged in and I wanna say it was 61 or 62 ohms but I forgot to write that down in my notes.
 
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