Many parts on many vehicles need some sort of a coding process when you replace them. It could be an oxygen sensor, it could even be a whole transmission.
On Toyotas, when you replace a transmission or transmission computer, you have to put in what's called a compensation code for that particular transmission so it knows how to shift properly.
Let's run through that process on this Rav4 right here. The tool is all hooked up and the ignition's on so let's go into Scanner and we're going to pick the Toyota auto Id. There's my vehicle, 2015 Rav4, and then that is inside Transmission.
Let's just say that we replaced the transmission on this vehicle or we were about to, replace the transmission on this vehicle, this is what we would want to do.
We can go in under the A/T Code Registration Read and Write Procedure. It says to make sure we refer to the shop manual.
This function is used to input a compensation code and initialize the ECU after a transmission assembly or ECU has been replaced.
You will have the following three options: read the compensation code, retrieve a saved compensation code from the scanner, manually enter the compensation code.
I click Continue there and then it's going to tell me what each option does so I'll just go through those really quick.
You want to make sure the vehicle is stopped, the gear selector's in park, engine is off and the ignition switches on.
All those things are good so we'll hit Continue and it says 'Warning: As the files will be saved with a title that includes the date and time it's recommended you keep your scanner updated with the correct date and time.'
So we'll just do that. We know that our time is correct.
It gives me the options and before I were to replace anything on this vehicle transmission-wise, I'd want to make sure I read the compensation code from the computer if I'm replacing the transmission.
So we'll do that. We'll take that code out.
It's going to collect the information. Here's your compensation code. It gives you a bunch of hexadecimal numbers.
Do you want to save this to the scanner? Yes, I do. Hit continue. It says 'Warning. You're going to want to write this down in case you have to manually enter it back in the transmission.'
We're not really actually changing anything, I'm just showing you the process, so we're good there.
Click continue. Here's what we're going to save. Is that correct? Yup. That's what was on the screen before. It's saved successfully.
Once I've saved it to the scan tool, then I'll go and do my repairs, replaced the transmission, whatever I need to be doing, and then I'll need to retrieve that saved compensation code that got saved to the scanner and program it into the new computer.
So we'll click on and then which one do I want to read or write? I already practiced this once. They're both identical, but I'll just pick the newest one right there.
You retrieved this file from the scanner memory. Is that the one you want to write to the transmission?
I sure do. Click continue. It wants to double confirm is that you're 100 per cent sure this is what you want to do.
So yep, I'm good with that. So hit correct. Continue. And it's going to verify a third time to make sure that this is really what you want to do.
Hit continue again and it will write it to the transmission. It says now resetting memory. It's also going to change all the adaptations that have been made with that transmission as well and reset them.
Resetting was completed so continue and it says 'Note: After code reset, you have to road test the vehicle to allow the transmission control module to learn new values. Follow the instructions on the next screen.'
Make sure you're doing it in a safe environment and make sure you observe all traffic laws, speed limits, et cetera.
Warm up the engine and then from a stand-still you're going to accelerate to the highest safe speed with the accelerator pedal about 15 per cent or less. Keep the accelerator pedal steady. Repeat until shift shock no longer exists.
Then from a stand-still, accelerate to the highest safe speed with it open by 25 per cent or more. Keep the accelerator pedal steady while driving the vehicle and do five to six until shift shock no longer exists.
That's just going to rewrite any of the adaptations for the shift points for the transmission.
And that's it. All you have to do is road test it to reset those values and your transmission is replaced, the codes are written and everything should function properly.