It is bang on 120 Ohms. The other end termination is also correct so that the overall resistance is 120/2=60 Ohms.

 

i’m not seeing where it says the Can+ to bat+ or gnd the limit is 10 K.

I’m looking at the 2002 to 2008 workshop manual for the S type which should be pretty close to whatever you have and it is showing the limit is greater than five ohms.

I haven’t got to anyplace where it has me measuring a voltage yet but I have an idea that that’s not a valid test because of the way the bus runs but I will continue to research

 

Just from a practical standpoint most buses are immune to noise that is coupled onto both lines it effectively filters it out. So even if you were seeing an offset voltage on both
Can plus can minus lines it might not make a difference. Where do you see a pinpoint test that asks you to measure the voltage on the Can plus or can minus lines?

 

Here are the pinpoint tests for the X350, Taken from the 6000+ page workshop manual:

G239843t24 : CHECK THE CAN + FOR SHORT CIRCUIT TO GROUND
1. Turn the ignition switch to the OFF position. 2. Measure the resistance between pins 06 (Y) and 04
(B) of the DLC. 3. Measure the resistance between pins 06 (Y) and 05 (BK) of the DLC.
· Is either resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t25.
G239843t25 : CHECK THE CAN - FOR SHORT CIRCUIT TO B +
1. Measure the resistance between pins 14 (G) and 16 (NW) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t26

 

Just to add the whole resistance check:

PINPOINT TEST G239843p2 : CHECK
THE CONTROLLER AREA NETWORK
FOR SHORT CIRCUIT
G239843t22 : CHECK THE CAN + FOR SHORT CIRCUIT TO B +
1. Measure the resistance between pins 06 (Y) and 16 (NW) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t23.
G239843t23 : CHECK THE CAN + FOR SHORT CIRCUIT TO IGNITION
SWITCHED +
1. Turn the ignition switch to the ON position. 2. Measure the resistance between pins 06 (Y) and 09
(GO) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t24.
G239843t24 : CHECK THE CAN + FOR SHORT CIRCUIT TO GROUND
1. Turn the ignition switch to the OFF position. 2. Measure the resistance between pins 06 (Y) and 04
(B) of the DLC. 3. Measure the resistance between pins 06 (Y) and 05 (BK) of the DLC.
· Is either resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t25.
G239843t25 : CHECK THE CAN - FOR SHORT CIRCUIT TO B +
1. Measure the resistance between pins 14 (G) and 16 (NW) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t26.
G239843t26 : CHECK THE CAN - FOR SHORT CIRCUIT TO IGNITION
SWITCHED +
1. Turn the ignition switch to the ON position. 2. Measure the resistance between pins 14 (G) and 09
(GO) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
GO to Pinpoint Test G239843t27.
G239843t27 : CHECK THE CAN - FOR SHORT CIRCUIT TO GROUND
1. Turn the ignition switch to the OFF position. 2. Measure the resistance between pins 14 (G) and 04
(B) of the DLC. 3. Measure the resistance between pins 14 (G) and 05 (BK) of the DLC.
· Is either resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
-> No
No short circuit fault found in controller area network. Check for DTCs indicating a module fault.
Carry out the pinpoint test for the module indicated.

 

You are quite correct. Both buses are quite robust. On the Can bus front my main problem is the low resistance compared to the test criteria. The manual states that the bus may work well enough to run the car when out of spec however programming modules will not work properly or at all. That is how this all started when I tried to program the ECM and it failed, and is now incommunicado!.
The voltage kicks in more in the SCP bus. It will work properly with problems in either line but not both:

PINPOINT TEST G239843p3 : CHECK
THE SCP NETWORK
G239843t28 : CHECK FOR CORRECT BUS TERMINATION IN THE SCP +
NETWORK
1. Measure the resistance between pins 02 (Y) and 05 (BK) of the DLC.
· Is the resistance 120 ohms?
-> Yes
Network resistance is correct. Check for DTCs indicating a module or circuit fault. REFER to the DTC
index.
-> No
GO to Pinpoint Test G239843t29.
G239843t29 : CHECK THE SCP + FOR SHORT CIRCUIT TO BATTERY
1. Measure the voltage across pins 02 (Y) and 16 (NW) of the DLC.
· Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t30.
G239843t30 : CHECK THE SCP + FOR SHORT CIRCUIT TO IGNITION +
1. Turn the ignition switch to the ON position. 2. Measure the voltage across pins 02 (Y) and 09 (GO)
of the DLC.
· Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t31.
G239843t31 : CHECK THE SCP + FOR SHORT CIRCUIT TO GROUND
1. Measure the resistance between pins 02 (Y) and 05 (BK) of the DLC.
· Is the resistance less than 90 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t32.
G239843t32 : CHECK THE SCP - FOR SHORT CIRCUIT TO BATTERY
1. Measure the voltage across pins 10 (U) and 16 (NW) of the DLC.
· Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t33.
G239843t33 : CHECK THE SCP - FOR SHORT CIRCUIT TO IGNITION +
1. Turn the ignition switch to the ON position. 2. Measure the voltage across pins 10 (U) and 09 (GO)
of the DLC.
· Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t34.
G239843t34 : CHECK THE SCP - FOR SHORT CIRCUIT TO GROUND
1. Measure the resistance between pins 10 (U) and 05 (BK) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
GO to Pinpoint Test G239843t35.
G239843t35 : CHECK FOR SHORT CIRCUIT BETWEEN SCP + AND SCP -
1. Measure the resistance between pins 10 (U) and 02 (BK) of the DLC.
· Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit. For additional information, refer to the wiring diagrams. Test the system for
normal operation.
-> No
Check for DTCs indicating a faulty module or circuit. Refer to the DTC index.

 

Damn. It is different. So that sucks.

start unplugging things. Somethings gotta have a short. Im out of ideas

 

Thanks for trying. I have disconnected most modules. When one shows a possible problem I check the pins on the module itself. Unfortunately at that time all of the things that feed in are disconnected so may see a problem or not!
So far I think my REM and FEM have shorts causing SCP problems. Also the ABS module brings things down on the Can bus but is one that shows no internal shorts.