2006 VZ transmission problem

[mbannout]

Hello everyone and thank you for this great forum, it has been a great help identifying problems in my car and saving lots of money.

my car is a 2006 VZ commodore (175kw) and is at it again, my mechanic isn't able to find the problem:
1- gear is stuck in 3d gear (limp mode)
2- shifting gears manually works perfectly fine
3- error code on ODBII is: "P0756 - Powertrain - Shift solenoid "B" performance or stuck off"
the mechanic took apart and tested both solenoids, both working fine
4- clearing the codes doesn't do anything, they just come back after 2 minutes
5- disconnected battery for 15 minutes didn't fix the problem

my mechanic thinks its the TCM but i feel he's just throwing random guesses at this point.
please help

 

[shueardm]

my mechanic thinks

You are either not paying him for his time or he should not be your mechanic,
I think you need to face facts, this is probably going to be a transmission fix that costs a lot of money, maybe even a couple hundred just to diagnose. Go to a transmission specialist is my suggestion.

 

[Benboy]

ditto - Consult an Auto Transmission Specialist before throwing any more money at it. Good luck.

 

[Benboy]

ditto - Consult an Auto Transmission Specialist before throwing any more money at it. Good luck.

 

[Pollushon]

If the box shifts fine manually then your fundamentals are okay. Most likely one of two; the PCM is the issue as it controls the solenoid or his test failed to identify a dodgy solenoid. Auto trans specialists will figure this out.

When the PCM thinks it had a dodgy solenoid it'll go into limp mode

 

[mbannout]

thanks for all the replies, i took it to 2 transmission specialists and both say it is most probably the Impeller that is damaged, but to be 100% sure they need to take it apart. its gonna cost a fortune to fix or replace

 

[lowndes8]

Shouldnt cost that much mine cost $1350 to pull apart, replace any worn, rebuild then fit it back into the car

 

[mbannout]

thanks for all the replies, i took it to 2 transmission specialists and both say it is most probably the Impeller/torque converter that is damaged, but to be 100% sure they need to take it apart. its gonna cost a fortune to fix or replace

 

[mbannout]

, $1350 is too much given the total value of the car

 

[mbannout]

, $1350 is too much given the total value of the car