maxs

ive been here in the past about the shifting problem with my hhr its an 07 2.2l auto. and it will not shif out of 2nd gear all shift lever gears work but put it in drive and it shifts smooth from 1st to 2nd and thats it nothing else no shifting no slipping at all.....

but it dawned on me because it was second hand ( bought it with a blown engine) to check the vin number in the window and see if it matched up with what was stored on the ecm ...guess what NO!!!

the one in it is from a dang cavalier....now the gear ratio i know is off..but my question is this will this stop the ecm from telling the tcm when and where to shift ?

and if so ill invest in a new unit for the car...

thanks for all your help...i love this forum

donbrew

Check on eBay, there a re a couple of vendors that can supply ECMs flashed to your VIN, for less than a new unit + flashing. About $100.
I imagine they could flash your unit for a small fee.

To answer your question, maybe.

I wonder about the TCM. And the solenoids.

maxs

well the solenoids was my first thought and changed them then i changed the tcm from a juniked hhr of same model nothing ...so i just for giggles checked the vin stored against the one on the car and they did not match so im hoping that having either this one flashed or a reconditioned unit will fix this issue ...

thanks for your quick reply

donbrew

Sounds like you have some sort of scan tool. First I would check for pending codes while driving when it fails to shift to third.

Check the ground connections on the top left of the trans and on the left side of the radiator support.

maxs

yes i do i have software on my laptop to read codes and log data in realtime... but i did follow the codes and replaced the solenoids... i took every gnd wire loose from the engine tranny and body check them and polished them and reinstalled them ( time consuming) but i did it anyway ...the power steering problem left but not the shifting problem...if its not the ecm then the tranny has to be rebuilt or replaced....but it would seem to me if the forward clutch assy is burned out it would still shift to third and slip...but idk

donbrew

A good trans shop could tell for sure.

I don't know much about transmissions. As far as I can tell the ECM has little to do with the shifting.

Will it shift manually? Not clear if it shift to 3 & 4 manually, maybe the cable?

Did you check the pins in the TCM connector and the trans connector?

How about the shift switch on the trans?

For reasons unknown the 2-3 SS solenoid is not activating, It only is activatedd in 4 or 3, the 1-2 SS solenoid is activated in P,N,R,1. There should be a DTC; P0752,P0757,P0976,P0977. If the signal is being sent to the solenoid. So, I'm thinking the switch or the linkage or the external wiring.

Oldblue

A Cavalier had a 4T40e transmission the HHR came with a 4T45E transmission the 40 doesn’t have the overdrive.
I own a 2003 Sunfire GT and the 2007 2.2 HHR LS and there’s a difference forsure.

maxs

i had it reprogrammed anyway and nada still same ... heck it was just a thought worth a try anyway...but how the heck did it get programmed for a cavalier anyway ...the part number on the ecm is for an hhr , cobalt, ect... go figure... but to answer the above questions yes i did run down all the wireing harness to the transmission and the tcm ( no broken connections...chkd all the cables for the switches from the top connector for the manual shifter ( just to be on the safe side) im going to attempt to build a signal monitor to make for dang sure the transmission solenoids are receiving the signals needed to shift...as my software doesnt have that option...if all chks out on that end then im assuming either a rebuild or replacement tranny but before that ill attempt to electronically activate the 2-3 solenoid manually (if possible without damaging the ecm or tcm) may have to disconnect the terminal wire for that particular solenoid first then after the 1-2 shift has completed get car up to speed then apply gnd to that wire it should activate ( i think) but thats only my next step if the tranny isnt receiving the correct signal

Oldblue

Is the TCM program for a Cavalier or the ECM or both?
Is it possible that the engine and transmission are out of a Cavalier, which would be incorrect for the 07 HHR

donbrew

The tag may still be on the transmission on the bottom.