CAT 950G No output from ECM to starter relay

[Brian Bobb]

Can anyone help me figure this out. Power from the key switch is going into the ECM through wire 307 but no output from 306. G763 and G764 has ground but it just won't send the output to start the engine.

 

[ahart]

Do you have ET to be able to see what the status of the parking brake and FNR switch is?

 

[Nige]

Also it would be nice if you posted a machine Serial Number, or even better the Publication Reference to the electrical schematic, so that we could look at the same thing you are.........

 

[Brian Bobb]

Do you have ET to be able to see what the status of the parking brake and FNR switch is?

Sadly I don't.

 

[Brian Bobb]

Also it would be nice if you posted a machine Serial Number, or even better the Publication Reference to the electrical schematic, so that we could look at the same thing you are.........

6JK01798 is the serial number for it. Oh I don't know the publication reference just the starting starting system and the park brake wires numbers I got from a guy.

 

[Brian Bobb]

I think that was the engine serial number. 2JS00349 is the machine pin number.

 

[Nige]

6JK01798 is the serial number for it. Oh I don't know the publication reference just the starting starting system and the park brake wires numbers I got from a guy.

Sorry I thought you were looking at the electrical schematic when you quoted those wire numbers. I'll send you an appropriate schematic.

 

[Brian Bobb]

Sorry I thought you were looking at the electrical schematic when you quoted those wire numbers. I'll send you an appropriate schematic.

Thank you.

 

[Brian Bobb]

Is there a way to check the FNR without the ET?

 

[Shivan Dookeran]

Is there a way to check the FNR without the ET?

hey id love a trip to stl .... im right next door

on a real it could be the fnr switch

 

[Brian Bobb]

hey id love a trip to stl .... im right next door

on a real it could be the fnr switch

You're right next door? Dominica? Saint Vincent? Trinidad? Lol. How can I go about checking the FNR switch? When I use a multimeter and check the wires from the switch, the ground connects to neutral and disconnect when you switch to either forward or reverse.

 

[ahart]

Looking at the schematic it sounds like the switch itself is working correctly, I would check the wires from the switch connector to the ECM connector. I’ve seen a few harnesses break in the steering column and cause issues.

 

[Brian Bobb]

Looking at the schematic it sounds like the switch itself is working correctly, I would check the wires from the switch connector to the ECM connector. I’ve seen a few harnesses break in the steering column and cause issues.

I checked the wires from the FNR and the keys witch, they both are sending the ground and the power when you turn the key to the start position. I checked the schematics that I got from Nige and 306 is the one that sends the output to the starter relay but nothing is coming out from that. I honestly don't know what else could be the problem. Also it is a new ECM that was installed.

 

[ahart]

Parking brake? What was the reason for the new powertrain ECM?

 

[Brian Bobb]

Parking brake?

I am getting continuity with the ground wire for pink wire marked G764 and no continuity with the yellow wire marked 419 and the ground wire.

 

[ahart]

That tells me that your parking brake is off.

 

[Brian Bobb]

That tells me that your parking brake is off. View attachment 276239

It should be one? I've played with the switch and even disconnected the plug and it still will not crank the engine.

 

[ahart]

Hav you tried a jumper wire between the black and yellow wire?

 

[Brian Bobb]

Yeah, I tried jumping the black and yellow wire and the ECM still refuse to send power out the green wire marked 306. What else could possibly cause it to not want to crank?

 

[Nige]

Parking brake? What was the reason for the new powertrain ECM?

So what’s the story behind the replacement powertrain ECM Brian.?
Is it new.?
Is it flashed with the correct software.?
Do you know what P/N of software is installed in it.?