re: check engine light and AT light question conundrum

[gramps]

Hello.
About 6 months ago, i got my first check engine light. The light would stay on when the car was started until it was shut off. Maybe 20% of starts would the light be on.
My mechanic pulled the code. it was #PO138 (oxygen sensor circuit voltage: high). He said a new unit was about a $250 part if it fails and told me to keep an eye on it. (he told me it was not urgent)

The car is a 2006 hatch auto trans 5 speed. Today a new issue with the car. I wonder if these two are related.
What happened was, I was cruising in 4th, and suddenly the car shifted in 3rd, with only a slight jerk while the check engine and "AT" light came on. The "AT" light remained on for about 1 minute, and then turned off, while the check engine remained on. Of course, i haven't pulled the new code as of yet.

I am wondering is it possible that the high voltage is somehow related to this new issue? My mechanic is new to me, and i am wondering, if this is a sort of thing to take in to a dealership.
any insight is useful
Thanks.
-g

[aarnone]

The P0138 code is for the rear oxygen sensor after the catalytic converter

I would recommend scanning the codes again and seeing if the same code came back and then look at the possibility of a bad O2 sensor

As far as the AT light I would look check if there are any transmission related codes in the computer at the same time

[Souls]

I have the same issue from time to time... haven't pulled codes yet. I disconnect my battery, then it's OK a few minutes to a few days, but it's getting worse, a serious PITA when on the DVP or 401

Just called the stealership, I hate when they talk to you like you're stupid. I simply asked how much to pull the codes.. "well that could be dependant on the diagnostic" I don't want diag's, I want the codes only $107/hr F' that, takes 5mins to plug in and download

[stock3]

The two codes are unrelated.
How is the ATF level and when was it last changed? If unknown, check and get back to us.

[Jackal]

You may be due for an Auto Transmission Flush on that shifting issue.

[TheMAN]

the price you pay for simply getting the dealer to pull codes is better spent on investing in a scan tool yourself and pulling the codes yourself.... after the first time it has already paid for itself!
now if there was a real issue you can't DIY fix, then take it to someone to fix of course! Their "diagnostic fee" will work towards any repairs

[peterm15]

the price you pay for simply getting the dealer to pull codes is better spent on investing in a scan tool yourself and pulling the codes yourself.... after the first time it has already paid for itself!
now if there was a real issue you can't DIY fix, then take it to someone to fix of course! Their "diagnostic fee" will work towards any repairs

Best advice

[Booter22]

You could be doing damage in leaving it or clearing it every few days with a battery pull. Ive seen dirty fluid block a sensor and a flush corrects it. That sensor needing replacement. Right up to tranny replacements. Get it scanned right and get it fixed fast before it causes you more money and a tranny replacement down the road. Usually most places will charge you diag to pull the codes and find the failure. Now you could be charged twice for diag in looking into the engine light and at light. Or worry anout only the at light if you know whats going on. But in even pulling the codes for the at light might not exactly be clear to what the failure is as there is always more then one possibility per code.

[MazdaMike02]

I absolutely hate bitching about people having to pay to pull codes. Do you have any idea how much OEM level scanners cost? Probably not. The software for ours is free but the tools to use the software cost upwards of 2500 dollars...and thats a cheap scanner. The reason why you have to pay? So businesses can stay in business after purchasing these expensive essential tools. If you don't want to pay, buy yourself a cheap little code reader.. I have a Launch one it was 60 dollars. Also Mac and Matco also have little code readers for cheap.

We need the code. More than likely it'll have a shift solenoid code. These are usually fixed by doing a transaxle flush. I've also seen a throttle body issue trigger the AT light as well..but you would know for sure if it was a TB. The car would go into limp mode with limited throttle input, probably wouldn't go over 2000 rpm either. I believe a major problem with the transaxle will also trigger a limp mode and AT light on.

[MazdaMike02]

Argh I meant hate seeing people bitch. Whatever, end rant.

[Booter22]

Argh I meant hate seeing people bitch. Whatever, end rant.

Exactly!

Its one thing to pull the code. Ok here it is p02727 say. Now what do you want to do. Spend hours on google seeing the different ways people fixed it or have the tech trained to fix it do the diag and tell you.. its not so simple to get the code and say here it is. Some codes can have 30 possible causes and 50 or more or less pages of diag to find out which repair is required. Trust me. I wish it was simple and the magic answer jumped out of the car. But it doesnt work that way.

[MazdaMike02]

Yep. It does in the truck and coach industry :P they have specialized scanners that literally diagnose problems for you and tell you where to look. They also located wiring issues.

Thats why you pay 1h diag, you pay for me to scan the code and diagnose it for you properly. It doesn't matter how long it takes, these are specialized tools, we work flat rate (payed per job), this is how we make our living. I always think to myself, would you guys like it if someone came to your work and whined about paying you for a service? You'd get pretty annoyed right? Not all of us are crooks, some of us are here taking care of customers and trying to make a life.

[gramps]

when i brought it in, it turned out to be two separate issues. The oxygen sensor issue was never going to clear permenantley, and i figured, i need my check engine light cleared to see any future issues that may occur. The sensor tip was "smoky" looking when we pulled it out.

About the AT question, i had a proper flush about 40k kms ago, replaced with amsoil AT. I remember reading a while ago that many people replace every 50k. The issue had to due with the sensor for the "rev limiter" if i remember correctly. Some of my gear shifting was not the smoothest. I just replaced it, since it was not too expensive.

-g