E38 OS with T42 TCM

[gmh308]

Sorry Newbie here and you guys are way beyond me but I needed no less than 5 heavy gauge grounds to the motor all directly run to the negative terminal on the battery before the fuel injectors began firing. I had spark and crank but no fuel pumping. L92 with 4l70e. Such is the blessing of a non conductive all aluminum motor.

Newbie? LOL you've been through the wars already !

5 grounds. That's wierd. Normally a well designed harness has a common ground bus throughout and grounds to the motor in two places (redundancy) and then motor to battery. Aluminum is not as good a conductor as copper but it still conducts very well. In fact AL is used for electrical conductors where light weight is key.

Cheers

[68problemchild]

3 grounds did not do it for me. What worked, Heavy gauge grounds:
1 ground to each head (Driver Rear/Pass front)
1 ground to front of lower motor
1 ground sub frame
1 ground body

All joined on Batt neg terminal. Check the injector voltage while cranking for each bank, no or spotty voltage = insuff ground. You must have a ground to each head.

[joecar]

Are all the ECM ground pins connected to ground...?

[Taz]

Just read post #39 ... that's quite the communications route ... may just stick with Gen III swaps !!

Regards,
Taz

[mbsurfersc]

I could see where the ground things may be a problem, but this is a 2009 Escalade were talking about. Everything in the engine harness is 100 percent factory including the E38. The only difference is instead of a t43 it now has a t42.

I think our problem is within the can bus communications. I'm going to look over the schematics now and double check the wiring in of the t42

[Taz]

Agree .... problem seems to have started when the T42 was installed.


Regards,
Taz

[68problemchild]

Hey don't give up. It can be done. I am living proof!

Now on my 07 escalade I had two full separate harnesses, one for bat-alt-grounds, one for the ECM, sensors and controls.

In either case, for me it was all in the injector voltage which was spotty on the logs when cranking. Its either there all the time or its not. In my case the grounded bank was firing and the ungrounded bank was not.

Again, I know very little so if your problem is elsewhere, that is cool. Just want to make sure you don't spend a month on it like I did only to find it was not a ECM issue at all.

Good luck!!!

[mbsurfersc]

Well after battling this thing for a while yesterday, bombing one E38, and banging our heads against the wall, we came to the conclusion of running a standalone transmission controller. I purchased a new E38 and flashed it with a 2010 Manual cal and it fired right up, no lights on the dash, everything fully functional.

I really do appreciate everyone's input and help through all of this! I will let you know how this thing does when it comes time to make power. Its a pretty bad ass setup:




THANKS AGAIN GUYS