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2004 Mazda 3, 4 door sedan, Check engine light on, AT light

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2004 Mazda 3, 4 door sedan, Check engine light on, AT light on intermittently, Codes are PO126, PO128, PO455,PO715, PO745, PO2187, PO2195.  Mechanic said the  455 and 2195 referred to evap and system lean?  He replaced the purge valve.  Both warning lights were off for 7 days, now both lights are on again. Transmission slams when put into reverse.  Besides that, the car drives fine.  What is the real problem and can it be repaired without going to a dealer?

Welcome to just I'm here to help you and your 100% satisfaction is my goal.

the canister purge solenoid if is associated with the 2187 code . The other codes you have Are all a little different , you have one code that pertains to a valve body problem in the transmission of the other transmission code may possibly be a faulty turbines sensor in the transmission to .And the first two codes are usually caused by a faulty throttle assembly

We need to do some diagnostic testing but you may want to start by disconnecting the battery and do it complete System reset by disconnecting the battery and touching the two battery cables together for 30 seconds this will completely discharge and reset All the modules in the vehicle . After that reattach the battery and see if the problem still persists

Car expert, ASE Certified Technician
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Customer: replied 6 years ago.
As far as the various things you mentioned, faulty turbines sensor, faulty throttle assembly and the purge solenoid which he supposedly replaced, if I do what you suggest as far as resetting the system, and the lights go off, does this mean it is corrected or just reset for a while? MAke sense? In other words, could this reset eliminate the lights, but not what is causing them?
Yes resetting the light or resetting the system will not solve the problem but what I would like to do is see what the first code is that pops up after you reset the system . So we can start with the most important thing first
Customer: replied 6 years ago.
I am at work at the moment. Let's say after work I was to reset the system as you suggested, I will have to wait until the check engine or AT lights appear before having the codes read, correct? Are the local auto parts store's (Advance or Auto Zone) code readers pretty reliable? Just stop at one as soon as the light appears? How do I send the info to you later or tomorrow?
That's exactly what you need to do reset the system and as soon as the light comes on stop into an auto zone and have them read the codes and give me a list of what popped up first thank you
Customer: replied 6 years ago.
O.K.. I can locate you easily whenever I log back on, correct? I just open this dialog page and send you another message as a "Reply"?
yes exactly
Customer: replied 6 years ago.
If I "Accept Answer" at his point, am I charged the initial amount 1 time again($23.00) or 3 times for each subsequent reply?

last reply= $23.00?


3 replies = $69.00?
You accept now and you'll only be charged once the $23.00 and that will cover us for the entire problem
Customer: replied 6 years ago.
Although I will not punch the "Accept Answer" on this page, the money has been transferred according to an email I received from "Just Answer". I am not stiffing you, I appreciate your help and will be getting back to to when the check engine light reappears. Thanks!

Thank you

Customer: replied 6 years ago.
Hi Sean,

I'm back with some answers and need to know what is true and what is not...

Mazda dealer as told me the code PO745 means the Pressure Control Sensor in the transmission is "stuck" or somoething and the entire transmission must be replaced for 3 grand. That is nuts. Each morning the "AT" light appears when the car is first cranked. After it has been running a little while, I can kill the motor and restart and it does not appear and rarely comes back on the entire day. Seems to only come on after car has sat for long time. Dealer also says the 128 code means the thermostat needs replacing as it is in the "Open" stuck position. They want $350.00 or so to do this. Isn't this exorbitant? Can't the transmission sensor just be replaced? He says it's too complicated due to having to break down the transmission to get ti it. Is this true? Whaqt can you tell me about these problems.
The 745 but in a faulty line pressure control solenoid, Test the resistance of the pressure regulator solenoid at the transmission connector. the resistance should be 2.4 - 7.5 ohms. The solenoid or internal transmission wiring harness may be faulty if the resistance is out of range. Remove the valve body and then inspect the resistance of the solenoid directly instead of through the harness, this will tell whether the solenoid is really bad or it is a harness issue. For the 128 replace the thermostat and clean the throttle body assembly

Edited by SEAN on 8/19/2010 at 6:46 PM EST

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