[gbalthrop]

Originally Posted by michaeldp

... we were able to get some voltages out of the pins you were looking for. The extra one that we tested was the one with corrosion (white/green wire), and it has no voltage so we weren't sure if it's a ground cable. Also not sure if ignition ON means turning on the car and testing, will do that once confirmed. Thanks again for all the information.

"Ignition ON" means Press START button WITHOUT pressing Brake/Clutch. That Activates Ignition & Lights Instrument Cluster, but does NOT Crank Starter to Start Engine. That Activates KL30G relay on JB Fuse Panel. Note the small "30G" above the Fuse Symbol for F26 on the ISTA diagram. THAT means that fuse F26 is powered ONLY with Ignition ON & KL30G ACTIVE.

I can't tell from the ISTA wiring diagram EXACTLY what the function of the White Green wire at X1746/3 is, but it appears related to RR Wheel Speed. I have NO idea HOW to test that signal, but I would NOT worry about that, as UNTIL the DSC functions (Power & Bus connections, and appears Yellow or Green on Tree (NOT Red), there is probably NO output on White/Green wire anyway.

If All 3 fuses are OK, & you have 12V+ at the 3 supply wires at X1746/25, 1 & 7, then if Brown Ground wires are OK (continuity to Chassis Ground), look for corrosion/ damage at the 4 Bus Wires.

Please ask questions about anything that doesn't "Make Sense" to you.
George

[gbalthrop]

Need to Add something to your "bag of tricks" for Electrical Testing: "Continuity to Chassis Ground"

For Voltage to be supplied to an Electrical Component, you need: (1) B+ (Battery) Voltage via the Red/x wires:
here Red/Blue, Red/Yellow & Red/Gray, but for the electrons to "Flow" and get BACK to the Battery (-) Terminal, you
need path to the Chassis (which is connected to (-) Battery Terminal). That's where the Brown "Chassis Ground" wires
come in. There are ~ 20 Chassis Ground points (studs with nut) on your vehicle. Attached is a "Component Location"
diagram for X170, which is the Chassis Ground Location to which the Two Brown wires from X1746/13 & 38 attach.
Make SURE the two Brown wires are connected snugly by Nut at X170

Test "Continuity to Ground":
1) Multimeter has Ohms/Resistance settings; Select Ohms/ Symbol "Ω" (Omega/Greek) & Intermediate Range,
e.g. 2k/2,000 Ohms;

2) Test Meter by touching Red & Black Probes together. (a) Meter reads "1" or ∞ (Infinite Ohms) when circuit is OPEN/
NO Continuity; (b) When probes are touching, circuit is "closed" & you have "Near-Zero" Ohms/ virtually NO Resistance,
or "Continuity". You can test for any "break" in the wire by testing for "continuity", probe contacting each wire end.

3) BEFORE testing continuity, remove Power Supply from wire, or disconnect Connector (here X1746 at DSC).

4) Test for "Continuity to Chassis Ground" by putting Red Meter Probe on Metal Socket of Brown wire (X1746/13),
and Black Meter Probe on any good Chassis Ground (metal), such as X170 stud. Repeat for X1746/38.

Please let us know what you find.
George

[michaeldp]

Originally Posted by gbalthrop

If All 3 fuses are OK, & you have 12V+ at the 3 supply wires at X1746/25, 1 & 7, then if Brown Ground wires are OK (continuity to Chassis Ground), look for corrosion/ damage at the 4 Bus Wires.

Please ask questions about anything that doesn't "Make Sense" to you.
George

Double checked the fuses, all look intact. See attached pictures

Inspected X1746/37 & 24, X1746/26 & 14, all looks good with no broken pins or enlarged sockets. Connector is all normal, from the imgur pictures.

X1746/13 & 38 continuity: All good. Attached updated diagram.

And I don't see any damaged & corroded cables or sockets, besides X1746/3.

[michaeldp]

Originally Posted by gbalthrop

Please let us know what you find.
George

Does it need to be with accessory mode ON? I did it with accessory mode OFF.

[michaeldp]

Anything else I can do?

[michaeldp]

bump

[michaeldp]

Just an update for everybody, I took it to the dealer again (free diag this time because I have already paid for $250 for them to try and fix) and they determined that DSC module has failed and quoted me close to $7,000 to replace.

I think I will try using NCSExpert and try to overwritten the .MAN file to see if it will communicate again. If that doesn't work than I will start working on replacing the DSC module with a used one. Will report back again when I have done so.