No trans gear enegage on 2011 colorado swap

[Assjoel]

Hi all,

Did a V8 swap to a 2011 Colorado from 2003 Suburban with current performance harness and computer programing. Motor operates fine but I cannot get transmission to engage any gear. ECM is E40 and TCM is T42. Transmission is from same junkyard suburban as the motor, did not see either run.

I put a new filter in transmission. I have overfilled the transmission to make sure the pump primed. Level seems to go down when running. if wheels are in the air they do seems to spin when in gear but slowly. On the ground it does not move at all when in R or D at idle or with RPM.

Scan with transmission channels attached, as well as tune. Anyone have any ideas ?

Thanks,
Joel

[blindsquirrel]

What special workaround did you find to make you think a 13-pin transmission - assuming this is a 4L60E, since you didn't mention it - will work with a TCM for a 15-pin 4L60E?

What are the chances the Suburban ended up in the boneyard because of a dead transmission?

[Assjoel]

Very good points. CPW told me to use that transmission rather than the 4L60E that was in the Colorado to begin with. I realize that I would need to change the bell housing and input shaft (swap parts with the 03 4L60E). The conflict might be the internal park/neutral switch on the 2011 4L60E?

The engine had a dropped valve, so I was hoping the transmission was the good part.

[blindsquirrel]

Unplug the round 20-way connector at the trans, this puts it into limp mode and with no power to anything it should default to 3rd gear in drive. If it doesn't do that it's an internal mechanical problem.

I do think you will need to get a different trans, 15 or 17 pin, if you want to keep the T42.

[Assjoel]

FWIW, the tranny does work in reverse and fwd when unplugged (limp Mode). I guess I will look into a 17 pin compatibility with T42 and how that affects wiring harness. and also how to change 17 pin 4L60 from I4 input shaft and bell housing to LS.

[blindsquirrel]

The 2006 5.3 Trailblazer your tune file is from would've used a 15-pin trans, if you want to keep things as compatible as possible.

Do you have wiring diagrams/pinouts for all the various different platforms you've combined here?