I have a 2000 GMC 1500 Z71 that came with a 5.3
I just had a shop put a 6.0 LQ9 from a 2003 Escalade in it.
When finished, the transmission shifted real hard and would not kick down .... would shift quick even on the floor.
Shop thinks they broke the cruise module
it has Cruise Control Module 25315559 SA

I found this pic on google and it also shows the string laying loose ... is this normal?

What could be wrong ..... I asked to shop to check for blown fuse?
Could it be ECM?

Here is the pic off google .... mine is just like it .... string dangling and all.

 

We checked for pinched wires and blown fuses .... nothing found.
Also, we hooked a scanner up to look for codes and nothing found.

It ran fine before the engine swap, now the LQ9 6.0 IS A DOG, slower than a 4.3 with 3 plug wires off!!!!!!

I sent a PM to my tuner ...... could it be the PCM tune as that and the long block is all that changed?

 

Hi ACAMS,

I've not seen that module before. Where is it located? I ask because I'll be replacing a shift lockout solenoid in the near future, which is in the steering cluster. If it's nearby, I can take a look at mine and see. The rig I'm working on is a 97 K1500 Suburban. They have a fair chance of using the same part.

Also, I would lean more toward a throttle position sensor as the culprit, but I'm not an expert.

 

TPS very possible

 

I didn't see this before my reply. Sorry.

The PCM could certainly be a problem.

 

I found out that is the cruise control module, and the cruise works fine.
It is located on the firewall by the steering column.

I replaced the TPS and have a fresh hot battery ..... still same problem.

I am starting to lean toward my new ECM flash and have PMed the guy that did the PCM.

 

This all sounds like a PCM and/or tune problem as these control when the trans shifts.
If you go WOT, at what RPM do upshifts occur?

 

REAL QUICK ... I didn't look at the tach, but in the 2000 range.

Also, it is a total dog even if I jerk it down and hold it in low.

 

That indicates a major sensor problem (TPS or MAF) and/or a tune problem perhaps related to final gearing ratio.

 

Well, I think it must be the tune, it ran fine until the swap to the bigger engine and now it wont even get out of it's own way, much less pull my boat.
I don't know anything about tuning and the guy here in town that tuned my 5.3 wants $600 to tune the 6.0... that is why I sent my PCM off for a tune.