Hi all,
I've got a question that I'm not sure has an answer.
I want to control the automatic transmission in my 2007 HHR manually. There isn't an option currently equipped in the vehicle to do so.
I suppose that this being possible depends on whether or not the vehicle has any provision for such a feature, and if not, what currently controls the transmission. I believe, like most modern vehicles, that it uses solenoids to control the ratio, so theoretically it is possible. That of course would depend on the kind of controller Chevy has and whether it plays well with others (I imagine not), and what kind of interface one would need to access these functions. Does anyone have any knowledge, theoretical or practical, about such a project?
Backstory: I have been working with electricity and electronics since I was four. I have a great deal of experience, from digital electronics to commercial power to coding, both professionally and otherwise. Normal "leave it to the professionals" jobs don't scare me, because, well, I am one. Not in automotive, but electronics are electronics. As long as the basic precautions of working with any digital, high reliability system are respected, no problems will ensue.

Thanks!

 

The problem with a project like that is the high level of integration with the different computer systems. Direct hardware control of the solonoids alone wont account for engine and body control modules working together with the transmission. I think there may be a possibility in software though. Tuner software such as Trifecta and HPT used for performance modification of the engine can also alter the shift points, and I know that Trifecta has the option to select tune parameters using the cruise control buttons which are connected to the powertrain module. Theoretically then the cruise control buttons might be able to select shift points, but I dont know of anyone that has tried, or even if it is possible, but you could try asking.
Trifecta and HPT have discussion forums that might help.
In the meantime, have you tried driving with the gear selector in "I"? It still doent allow for manual shifting, but raises the rpms to be more in the power band of the engine, and gives some engine braking.

 

Even though the "E" in the 4T-45E transmission stands for "Electronically Controlled", the only way to manually manipulate its shifts would be the stick between the seats.

As pointed out by prod above, there can be some control of shift point exercised by tuning programs, but only to a certain degree.

Electronics aside, the 45E is a fairly old design both in control arrangements and the number of ratios. Treated with kindness, and proper maintenance, they are pretty bulletproof units.

 

x2
moreover, this Transmission "slow on the uptake"
I'm no expert, but I think that if you implement your plan - you do not get a decent result. Transmission still be slowpoke.
On my penultimate car (Toyota), I actively used a stick forward / backward. This was justified, fast response.
Hippo in this sense behind. One good thing - do not asks double-team.

 

The best way to have control of the transmission is to get a hhr with a stick shift. Even the "auto sticks" on other cars isn't that fun.

 

And the OP has not been back since starting the thread.