Stub333

Since I bought my car the trans always thumped going into 4th gear, sometimes a little and sometimes severe depending on how far the accelerator pedal was depressed. The converter also never locked up after 4th. No big deal I thought, I would just let off the gas before the 4th gear shift to avoid the thump. The trans was rebuilt at one point so I figured the thump was normal since all rebuilt trannys perform a little different. The CEL was never on so I figured no biggie.
Recently the CEL came on so I decided to scan it with my buddys Actron scantool...it returned 3 codes, P1035(o2 sensor Bank1 Sensor1 heater), P0770(Shift Solenoid E Malfunction), and P0773(Shift Solenoid Circuit Electrical). I think the two solenoid codes were there since day 1, before the CEL came on for the o2 sensor.
I am not concerned about replacing the o2 sensor yet since it is just the heater but I definitely want to replace that solenoid. Do you think that replacing the solenoid will stop that thump, or is that thump form something else? Where is the best(cheapest) place to buy transmission solenoids? The dealer said that there are 4 total, and that they come in pairs.

Pheonix

You got it.

Stub333

What do 'I got'

Pheonix

tada!

IDK about shift solenoids, any auto-parts store is going to be way cheaper than OEM parts.

Stub333

I hope so...just curious as to why the shift solenoids do not cause the CEL to come on? Like before my o2 was my bad, the solenoid was, yet no CEL...

Pheonix

Depending on the issues, it's a 1-2 trip logic & it will cause the O/D light to go off.

Stub333

You need to explain things a little better, I have no idea what trip logic means, and I never had a O/D light issue...and it's a thump in fourth not 1-2

Pheonix

That is ECU slang for how a code is stored.
For explaination purposes, we can break every possible code/malfunction into two groups
Some codes, like anything ignition related, can be catostrophic failure that will take the car off the road. If they show up, the CEL will immediately come on
Other codes, while differening in severity, will not cause a catostrophic failure, nor keep you from getting anywhere. On these, the ECU will "wait and see" what happens over multiple drives, or one loooong drive before it decides to store the trouble code.

Trip logic is nothing more than how many short drives you need to take with a problem, before the ECU decides to let you know about it.
Some will do it immediately, some after one trip, some after several trips.

Stub333

Thanks for the explanation

lexclass2

i have the same problem then it just will not go into 4th gear rpm @3000 when going only 60 say maybe the ecu.. i hope getting this ecu for 200$ clear up my 'no shifting'

BadViper22

If you have the same problem then why are you talking about replacing your ecu? Thats extra money you don't have to spend and won't fix your problem if you are in the same boat as the original poster. Besides the obvious physical problem, do you have a CEL? Is your O/D Off light blinking?

GEORGE_JET

I agree, you may have the same symptoms, but the root cause of the problem may not be the same thing. Unless you run the proper tests, you will not know. Do you have a DVM? And enough mechanical skills to follow some test procedures? If so we can post documentation to narrow down the problem. If not I would recomend taking it to a mechanic.

At this point, swapping out the ECU may or may not fix the problem. Without testing you are taking a risk, and few stores will accept a return on a electrical item, especially a ECU.