I need to change the transmission modulator valve on a 2003 Chevy Impala. I need help with the location of the valve and even steps on how to change it. Thanks

The shift solenoid on a 2012 Chevrolet Impala is located inside the transmission. It is typically located near the top of the transmission, near the shift lever. In order to access the shift solenoid, you will need to lift the vehicle and remove the transmission pan. The shift solenoid is usually mounted on the side of the transmission and is connected to the transmission control module or the transmission valve body.

It is important to note that the location of the shift solenoid can vary depending on the specific model and year of your Chevrolet Impala. If you are not familiar with automotive repair and are unsure how to locate the shift solenoid, it is recommended that you seek the help of a professional mechanic.

Question edited for clarity.
Question moved to sub category.

Shown in the link. It is in the engine bay. More on the images tab.

https://www.google.com/search?q=2003+Chevy+Impala.+engine+control+module+location

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How to reset ECM TCM in 2012 Impala Chevy Impala Forums

It is under the rear passenger seat cushion, it is marked as item 3 in diagrams below.

Please verify the year of your truck. A 2003 Chevy Trailblazer has a 4L60E transmission. This transmission does not have a vacuum modulator valve. The 4L60 uses a vacuum modulator valve but the last year for that transmission was 1992. The perpose of the modulating valve is to control/regulate line pressure. The line pressure in a 4L60E is computer controlled or controlled electrically.

P0171 and P0174 are lean codes. There is likely a large vacuum leak or the MAF is bad.

Try starting the car and wiggling the connector for the MAF sensor. Also try tapping the MAF sensor. If the idle changes or the car stalls replace the MAF sensor.

The second shop should recognize that these codes don't have anything to do with the ignition module.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

He's back !!!

Inside the side cover on yours--- Jerry

No easy job- as sub frame is in the way, I
suspect

Need a trans shop

the clicking noise could be eiter a valve or piston. the smoke out of the exhaust means different things depending on the color and how much smoke. Check your air filter and make sure oil is not backing up into it. Also, it may be a good ideal to go ahead and change the oil even though you arent at 3000 miles, unless you just changed it. Change the PCV valve also, if itis clogged it will give you problems. Has the check engine light come on?

Did you have it serviced or rebuilt, If you had it rebuilt I would take it back to the trans shop for warranty repairs.
If they just changed the trans filter I don't think it would cause your problem.You just have bad luck with the slipping trans

Thats WAYYYYYYY too much money!!!!! I changed the PCM and thermostat on my Impala myself for about $125. Even if you had someone install it for you it shouldn't be much more than 2 hours labor. I'm not sure what car you own but the PCM shouldn't run that much.