Transmission Problem?

[Boris]

I can't find an appropriate newsgroup for this, but this is an 'OT' newsgroup, with smart mechanics.

I've got a 2013 Mazda CX-9, with 128K miles. It runs perfectly, but the check engine light has been on solid for many months. I had it diagnosed and it's throwing two codes, both related to the transmission. But, the transmission is working fine. No bumps, thumps, lags, etc...it's like new.

The codes are:

P0730 - Incorrect Gear Ratio P0977 - Shift Solenoid "B" Control Circuit High

My Mazda dealer tells me I have to replace the transmission...$9,000.

Anyone familiar with the codes, and if there is anything other than replacing the tranny will do?

Even though the codes do not relate to emissions, the state will not pass the car for it's annual registration.

Thanks.

[danny burstein]

Before anything further, have the mechanics "reset" the codes? Sometimes... sometimes... these errors are courtesy of an isolated, so to speak, "hiccup" and once cleared, don't recur.

Or... might recur a month later, meaning you could "clear it" Monday morning and get the inspection Tuesday.

(Yes, on most cars these error codes will clear on their own after umptity miles/hours of "everything ok", but not all..)

[Ed Pawlowski]

I'd try that first. Next would be a transmission shop, not a dealer. If it comes on after inspection, a piece of black electrical tape makes it much less annoying.

[danny burstein]

[snip]

Most, but not all... code readers do have a "reset the error" button.

I have a basic unit from HF which was something like $50 which reads and can reset the main drive/emmissions systems. Others have the ability to look at more of them

I've only bumped into one unit that didn't have the "reset" option, which was at, yes, a car parts chainstore that would give you a "free" inspection but could NOT do the reset.

Oh, and that was the one they'd offer to hand you over the counter if they thought you could manage it...

[micky]

Can we presume you google the code and followed all the hints? E.g.

**

The one problem is that if the light is on, you won't know when a new problem arises, likely one with emission consequeences. Is that the basis for their position?

If not, their position doesn't seem right. Originally the check engine light was only for emissions related problems, and my impression is that for cheap cars and cars as old as mine, 2005, that's still true.

But for fancy cars, more and more possibly, they decided to take advantage of the ligght and the OBDIi and report other problems.

What state are you in?

Is this the rule in other states?

Maybe you find the agency in charge and talk to the administrator and get the rule changed.

**"This is the most common failure point when looking at this trouble code. Transmission fluids are often called lifetime fluids, which many car owners think means that they never need to be replaced. This is, however, only a specific time period that the manufacturer has designated as the life of the vehicle." I have never heard of this before. I've only chaanged my fluid once in 60 years iirc, and then only because it wasn't working well and a friend said that might help. It didn't.

[hubops]

Some general info here :

As others have suggested - reset the codes and see if they return.

John T.

[Boris]

danny burstein [e-mail] wrote in news:trk4ma$kes$1 @reader2.panix.com:

I understand. What's odd is that my smog test guy told me that he couldn't reset the code and retest. I don't know why that is, or if it's true. I always thought the code could be turned off, the car started, and if it didn't show up again, retest. But he said that although the check engine may not reappear for a day or so, the codes that set off the check engine light are still in the car's computer, and they will not let the smog test pass. I've never heard of this. But, it does make sense that just turning off any codes and smog checking immediately there after, everyone could pass smog. Unless, the code was erroneous and intermittent. I also understand that a code won't reappear if the computer doesn't sense the same 'error' within the next xxx starts.

[Boris]

danny burstein [e-mail] wrote in news:trk7o7$9f0$1 @reader2.panix.com:

I did have a code scanner back in 2019. I loaned it out, not gotten back:

It will reset codes.

Before I re-purchase it, and turn off the codes, hoping that it will then pass smog, I think I'll go to another smog shop that I've used for years and see what they say as to whether or not the codes can be turned off, and if they don't return upon start up, can they do a smog test. The first smog guy told me, no.

[Boris]

[e-mail] wrote in news:kv9rthlqbehq1j6mslbrocfbfej7qnqak4@

4ax.com:

Thanks. I've been to that site for code explanations. The Mazda site only gives technical bulletins, and is very 'iffy' as to if my VIN has that issue.

It seems like one needs a very analytic mechanic that will go down the 'flowchart' to efficiently arrive at a fix. I do understand that this may end up being a replace and test, replace and test exercise, which may end up as a tranny replacement by the dealer (because they don't care to go down the flowchart), or a simple solenoid replacement (which does require dropping the tranny), by a non-dealer mechanic.

(I've worked in cars (rebuilding engines) until about 10 years ago, when I just no longer wnated to get under a car on jack stands scratching my nose, or bruising knuckles on extremely tight engine compartments with electronics that I didn't understand. No more.)

[danny burstein]

[snip]

The general rule for an OBD [a] (computer interface) deal is that... they've got to run for umptity hours and mucho differnet parameters (speed, acceleration, etmperatures, etc,) before the system will give an "all clear" to the Dmv computer.

So if you reset the error messages, you'll also resetting (at least with all legal scanners...) the entire array of readings, so yes, the car has to run another 100 miles and ten hours (numbers made up for illustration).

Note the same thing happens if you disconnect the battery, which in most cars will reset everything as well.

As far as I know the "bad info" that set off the warning lamps is erased when you do a reset, but whether or not that's the case, you will NOT get an "everything's ok" message to DMV until a clean 100 miles/10 hours (or whatever the actual numbers are.

In my own car's case, the catalytic converter was showing its age. So I'd do an OBD scan [b] before heading to the inspection shop. If there was a problem, I'd do a reset and then get readyi to head over two days later, doing another scan first...

[b] for some of the issues, the warning light comes on after _TWO_ separate readings that there's a problem.

That why you're not going to get bothered by a once-off "hiccup". However, that info is stored... until overwritten that ten hours later... And while still there, even if you don't see it, will flag DMV

[a] On Board Computer

[Ed Pawlowski]

How many miles do you have to drive after a code reset? about 50 to 100 miles Here's something you probably don't know: after clearing the car's computer you will need to drive for about 50 to 100 miles. As you drive your car the computer will monitor all the sensors and register the results.

[Jim Joyce]

When I needed to read & clear codes, I got the cheapest OBD2 unit I could find on Amazon. I think it was about $12-14. It's just a dongle that plugs into the OBD2 port and connects to my phone via Bluetooth. There's a free app (Torque Lite) that then turns the phone display into the OBD2 display. It does far more than I need, but for reading and clearing codes, it works just fine. I wouldn't spend more unless you really want to.

[Boris]

danny burstein [e-mail] wrote in news:trklfm$44s$1 @reader2.panix.com:

requirements.

Nice explanation. I didn't know that clearing the codes means there's no codes to report to the DMV until new codes (good or bad) are regenerated and placed in the car's computer.

Since the check engine light did go away a month or so ago, but now it's been on permanently for weeks, after driving many, many miles, that would indicate that it's not going to go away.

At this point, I think I'll see if disconnecting the battery does indeed make the check engine light go out. If it does, I'll just keep driving the car for a while (xx hours, xx miles), and if the light doesn't reappear, I'll test with an ODB2 scanner.

If the light does come back on, I guess I'll take the problem to a transmission specialist to see if this problem can be fixed without replacing the transmission.

[Clare Snyder]

The P0977 usually means a bad solenoid pack or a bad connection in the wiring harness between the transmission control computer and the transmission. If the shift solenoid does not actuate when commanded the transmission remans in the wrong gear, triggering the P0730 code.

Take the vehiucle to a different Mazda dealer or a qualified transmission shop. The shift solenoid B is the upper solenoid of 2 on the transmission valve body inside the transmission "pan". I would strongly suspect the solenoid to be intermittently deffective - quite possibly temperature sensitive - which could pssibly be determined by the obd tester by checking the recorded operating parameters when the code was triggered.

[Clare Snyder]

turning off the CEL also resets all the "monitors" which need to re-initialize before they can retest. You are generally allowed one or two failed monitors on a smog test. This is to prevent someone shutting off the cel just before going for the e-test. A teast only facility is NOT allewed to make any adjustments or perform any repairs. A full "drive cycle" is required to reset the monitors. If you are lucky the transmission solenoid code will not return before you get the monitors reset and the e-test passed.

Ignoring the transmission code is one way to guarantee you WILL eventually need to replace the transmission. Have a transmission shop check and repair/replace the solenoid

[Clare Snyder]

Both my Ford and my Hyundai can reset all monitors in 35Km under ideal conditions It canreset all but 2 in not ideal confitions - The most I have needed to get all monitors set was 2 full cycles - about

70Km. - but you DO need to have the fuel levels in the right range and the right temperatures. (iirc fuel between 1/4 and 3/4 full for evap monitor)

[Clare Snyder]

The cheap ones won't reed transmission, ABS, traction control or seat belt codes

[Jim Joyce]

I guess I got lucky then. I apparently have never needed to read any of those things. The OP obviously wouldn't fare as well.

[Boris]

Clare Snyder [e-mail]> wrote in news: [e-mail]:

Good advice, and that's what I plan to do, go to a qualified transmission shop (one that can go down the OBD2 diagnostic flow chart, and check all points along the way).

Thanks.

[trader_4]

That;s correct. There are emission monitors that get cleared when the codes are cleared. They have to be set again for it to pass. Some set very quickly, others need miles and/or drive cycles to set. The one that takes the longest is the fuel evap system one. That can take many drive cycles to set. In NJ I think late model cars will pass if all but one are set.

I would probably clear the codes, then if it's set again, take it to a transmission shop. It sounds like a solenoid problem and those can be easily replaced and it's not expensive.