Subaru Outback Forums banner

21 - 40 of 54 Posts

·
Registered
Joined
·
35 Posts
Temperature sensors are on the valve body. So far if the temperature sensors are bad on the valve body the valve body gets replaced. If there is an issue with fluid flow that's preventing the proper temperature regulation of the fluid then you have to find out what that is.

Look up p0712 and p0713.
Ok so I just text my Subaru mechanic again. I asked him if there’s further scans he can run aside from the one he did on that laptop and aside from him doing a relearn of the transmission. Btw he is doing this on the side for me and didn’t charge for the re learn or the original quick diagnostic. There are no codes like I’ve mentioned just a steady yellow “AT Oil Temp” light.
 

·
Premium Member
2001 VDC/SC One of a Kind
Joined
·
13,779 Posts
There could be a problem and the computer doesn't pick up on it so it won't set a circuit code. There could be an actual problem with the temperature regulation of the fluid and there's no code for that. Just a light. So in order to find it without codes you have to do Hands-On testing.
 

·
Registered
Joined
·
35 Posts
How long does it take for the light to come on and stay on?

And ask him to look up the p0712 and 713.
It comes on after about 40ish mins on the freeway (continuous) going 70+ mph. No changes in driving performance. I saw on another forum online that 2 people had nearly identical issues and they were both diagnosed failed valve bodies. Light subsides after I pull over and let engine idle for a minute or so OR if I restart engine.
 

·
Registered
Joined
·
35 Posts
So I have a 2014 Subaru Outback 2.5i Limited. It has about 104,000 miles. Whenever I drive on the freeway for at least 40 mins going 70+ mph, the “AT Oil Temp” light comes on solid. The light won’t disappear unless I pull over and let the engine idle for a minute or so OR if I restart the engine.
I had the transmission oil flushed 2 weeks ago to attempt to solve the issue, but it was to no avail. I then took it to a Subaru dealership and had one of the specialists run a full test (light went away when I arrived) and no current codes were displayed. There were “old” codes (COO42 and B1608) which turned out to be power supply from previous old battery and the sun load sensor (Minute codes).
He then did a relearn on the transmission. After driving again on the freeway for about 40 mins, the light came on solid again. I read online similar issues and they were diagnosed failed valve bodies. I wanted to see if anyone had any ideas to a cheaper alternative or any definite diagnosis’?
 

·
Registered
Joined
·
17,710 Posts
I saw on another forum online that 2 people had nearly identical issues and they were both diagnosed failed valve bodies.
It's sounding more and more as if there's been something faulty on a number of valve assemblies. Without further diagnosis, it's hard to confirm, but it could just be the temperature sensor element not sensing correctly when it gets warmer (over-indicating the temperature), or perhaps a valve or solenoid not working and preventing proper fluid flow, especially through the ATF cooler.

It's not that we don't believe it's possible in your case; rather, it's that given the cost to replace the valve body, I think we'd rather feel more confident about it. In some of the other cases, it was replaced under warranty, so I understand those car owners being less concerned.
 

·
Premium Member
2001 VDC/SC One of a Kind
Joined
·
13,779 Posts
On another note when you scan a system with just the key in the on position and not starting it a code that popped up on the last ignition cycle where the car was running will show as "old". If it's been a few drive cycles not seeing the problem it will show it as "older".

So maybe checking the grounds and the cable connection at the battery would be a good idea.
 

·
Registered
Joined
·
35 Posts
It's sounding more and more as if there's been something faulty on a number of valve assemblies. Without further diagnosis, it's hard to confirm, but it could just be the temperature sensor element not sensing correctly when it gets warmer (over-indicating the temperature), or perhaps a valve or solenoid not working and preventing proper fluid flow, especially through the ATF cooler.

It's not that we don't believe it's possible in your case; rather, it's that given the cost to replace the valve body, I think we'd rather feel more confident about it. In some of the other cases, it was replaced under warranty, so I understand those car owners being less concerned.
Yes, I agree. Back in regards to the other forum I mentioned, if I remember correctly, they did mention one of the solenoids failing, but sense it is sold as entire assembly, you must replace the entire valve body in order to fix just one issue such as a solenoid or a sensor.
 

·
Registered
Joined
·
17,710 Posts
Whenever I drive on the freeway for at least 40 mins going 70+ mph, the “AT Oil Temp” light comes on solid. The light won’t disappear unless I pull over and let the engine idle for a minute or so OR if I restart the engine. [underline added]
  1. When the light comes on solid and you've stopped to let the engine idle for a minute, is the transmission also shifted to P or N, or is it left in D?
  2. When the light comes on solid, and you pull over, turn the engine off, and then restart the engine and resume the freeway driving again (all in quick order), does the light come back on almost right away, or does it take another 40 minutes of 70+ mph driving for it to return?
  3. When the light comes on while driving on the freeway, if you exit the freeway and drive on a slower road (e.g., 45-55 mph) for some time without idling or restarting the engine, does the light go out on its own?
  4. Has the light ever come on when travelling on highways at less than 70 mph?
 

·
Registered
Joined
·
35 Posts
  1. When the light comes on solid and you've stopped to let the engine idle for a minute, is the transmission also shifted to P or N, or is it left in D?
  2. When the light comes on solid, and you pull over, turn the engine off, and then restart the engine and resume the freeway driving again (all in quick order), does the light come back on almost right away, or does it take another 40 minutes of 70+ mph driving for it to return?
  3. When the light comes on while driving on the freeway, if you exit the freeway and drive on a slower road (e.g., 45-55 mph) for some time without idling or restarting the engine, does the light go out on its own?
  4. Has the light ever come on when travelling on highways at less than 70 mph?
1. The light has gone off in both situations. I’ve parked the car on the side of the road and the light turns off or I come to a stop sign or red light and the light will go away after a few seconds.
2. I’ve pulled over, then parked and restarted the engine. I then continued to drive on the freeway and the light returned about ~25-30 mins later.
3. I don’t believe I’ve fully tested this scenario, if I have I don’t remember, unfortunately.
4. It usually comes on after being on the freeway at those high speeds 70*, (actually just turned on today after 35 mins 75+ mph) but there were 2 instances when I was on the freeway for 30ish mins pulled over to buy a drink/food then resume on freeway for about 15 mins and exit to slower feeder (~50 mph) and the light would then turn on.
 

·
Premium Member
2001 VDC/SC One of a Kind
Joined
·
13,779 Posts
It would be interesting to know what the engine temperature is when the light comes on. Do you have an Android app or scanner or anything that could read the engine coolant temperature reading from the computer? You can pick those little scanners up from the part store for about $30 or $40.
 

·
Registered
Joined
·
35 Posts
It would be interesting to know what the engine temperature is when the light comes on. Do you have an Android app or scanner or anything that could read the engine coolant temperature reading from the computer? You can pick those little scanners up from the part store for about $30 or $40.
So I had the valve body changed 4 days ago. I thought it would fix the issue but the light still came on. I had the Subaru mechanic who changed the valve body ride with me in the car until the light came on and he said the transmission is actually heating up (according to his computer- he had it plugged in while I drove). He says now it might be a wiring issue, bad Transmission module, and he’s also going to look into the P0712 and 713 codes.
IM JUST VERY ANNOYED AT THIS POINT BECAUSE I NEED TO TRAVEL.
 

·
Registered
Joined
·
17,710 Posts
I had the Subaru mechanic who changed the valve body ride with me in the car until the light came on and he said the transmission is actually heating up (according to his computer- he had it plugged in while I drove).
With the valve body replaced, which includes the temperature sensor, the sensor itself isn't likely faulty.

As it's not mentioned, I suppose the mechanic didn't compare the transmission pan temperature to the reading on the computer before heading out, and then again when the high temperature was reached on the computer readout (~270 F from your other post). Although the new sensor isn't suspect, the wiring harnesses between the transmission and the TCM could be faulty, causing a higher reading than the actual ATF temperature. The P0712 and 713 codes relate to wiring faults.

If the transmission is indeed still overheating, I think one would want to verify that the torque converter is indeed locking and maintaining the lock when travelling at the freeway speeds.

The condition of the ATF cooler lines, and the flow through the cooler might be checked to ensure there's sufficient movement to ensure proper cooling.

@cardoc 's suggestion to monitor the engine coolant temperature is also part of this.

In a recent post, a member confirmed that the ScanGauge II extended categories can display the ATF temperature as well as other PIDs for the CVT.

Get the old valve body back. There are members here who are occasionally looking for CVT valve body solenoids that are not otherwise available. You might be able to recover some of the cost of the new valve body.
 

·
Registered
Joined
·
35 Posts
With the valve body replaced, which includes the temperature sensor, the sensor itself isn't likely faulty.

As it's not mentioned, I suppose the mechanic didn't compare the transmission pan temperature to the reading on the computer before heading out, and then again when the high temperature was reached on the computer readout (~270 F from your other post). Although the new sensor isn't suspect, the wiring harnesses between the transmission and the TCM could be faulty, causing a higher reading than the actual ATF temperature. The P0712 and 713 codes relate to wiring faults.

If the transmission is indeed still overheating, I think one would want to verify that the torque converter is indeed locking and maintaining the lock when travelling at the freeway speeds.

The condition of the ATF cooler lines, and the flow through the cooler might be checked to ensure there's sufficient movement to ensure proper cooling.

@cardoc 's suggestion to monitor the engine coolant temperature is also part of this.

In a recent post, a member confirmed that the ScanGauge II extended categories can display the ATF temperature as well as other PIDs for the CVT.

Get the old valve body back. There are members here who are occasionally looking for CVT valve body solenoids that are not otherwise available. You might be able to recover some of the cost of the new valve body.
Ok thanks. That’s ALOT OF INFO lol.
alright so, did grab a thermal temp Gun and checked the pan at the end of our drive and that’s when he confirmed they were matching temperatures. He says he will check if it’s a wiring thing and also run the test for those 2 codes and narrow it down. He said worst case scenario it could be a faulty module. He will run the tests tomorrow.
Lastly, I kept the old Valve body just in case I were to need it, luckily! What are you saying I should do with it? (It’s in my garage)
Thanks!!
 

·
Premium Member
2001 VDC/SC One of a Kind
Joined
·
13,779 Posts
Subaru does not sell solenoids for these valve bodies. Aftermarket manufacturers like Rostra do not have solenoids. So, you post up for sale the solenoids on your valve body to recoup some of the cost you have in the new valve body. You did not have TCC issues or ratio change issues. Apparently you didn't have a temp sensor issue. So your valve body and solenoids are good.

$$$$$$
 

·
Registered
Joined
·
17,710 Posts
did grab a thermal temp Gun and checked the pan at the end of our drive and that’s when he confirmed they were matching temperatures.
If the computer indication and the pan temperature were close, then it's not the sensor, or the wiring (to which the two codes apply), andunlikely a fault of the TCM. Those would be suspect if the computer was indicating a high temperature while the actual measurement was significantly lower.

This all suggests that the ATF is indeed overheating. The ATF can overheat when the ATF cooler function is weak, and/or the transmission, incl. the torque converter, is generating an unusual amount of heat at the higher speeds.

The two lines to the cooler include both metal tubes and rubber hoses. These should be inspected for possible restrictions; e.g., a rubber hose that is collapsing at a tight corner, or a metal tube that's been compressed.
 

·
Registered
Joined
·
35 Posts
If the computer indication and the pan temperature were close, then it's not the sensor, or the wiring (to which the two codes apply), andunlikely a fault of the TCM. Those would be suspect if the computer was indicating a high temperature while the actual measurement was significantly lower.

This all suggests that the ATF is indeed overheating. The ATF can overheat when the ATF cooler function is weak, and/or the transmission, incl. the torque converter, is generating an unusual amount of heat at the higher speeds.

The two lines to the cooler include both metal tubes and rubber hoses. These should be inspected for possible restrictions; e.g., a rubber hose that is collapsing at a tight corner, or a metal tube that's been compressed.
Sweet, thank u for the info bro. I’ll definitely mention this to my mechanic today! I’ll keep u updated too. Haha
 

·
Registered
Joined
·
35 Posts
If the computer indication and the pan temperature were close, then it's not the sensor, or the wiring (to which the two codes apply), andunlikely a fault of the TCM. Those would be suspect if the computer was indicating a high temperature while the actual measurement was significantly lower.

This all suggests that the ATF is indeed overheating. The ATF can overheat when the ATF cooler function is weak, and/or the transmission, incl. the torque converter, is generating an unusual amount of heat at the higher speeds.

The two lines to the cooler include both metal tubes and rubber hoses. These should be inspected for possible restrictions; e.g., a rubber hose that is collapsing at a tight corner, or a metal tube that's been compressed.
Ok. So I’ve had him run diagnostics today and yesterday. He changed out the TCM (temporarily from a loaner) and I drove it but the light still came on. What was weird was I exited the freeway, never coming to a complete stop. I made a U turn at the underpass, (dropping to a speed of maybe 30 mph for 15 seconds) and then immediately got back on the freeway resuming 65+ mph. After about a minute or so, the light went off a never came back on while on the freeway for the next couple of minutes. Also, he checked the ATF cooler lines and cleaned them and said they were fine and if they weren’t working I would have no pressure. He says the transmission pan temp is reading about ~10* F less than what the computer is saying. But still, at that level the transmission temp got up to about ~260*F while we were on the freeway last week when he was running the test w the computer plugged in.

So his final guesses are we could change the wiring harness or the transmission itself just may be going out? But the thing is the car drives amazing and he even told me for its age and mileage it’s in great working shape (2014 2.5i OB, 105k miles). Even when the light would come on, I’ve never noticed a difference in driving performance. HELP!
 

·
Registered
Joined
·
35 Posts
If the computer indication and the pan temperature were close, then it's not the sensor, or the wiring (to which the two codes apply), andunlikely a fault of the TCM. Those would be suspect if the computer was indicating a high temperature while the actual measurement was significantly lower.

This all suggests that the ATF is indeed overheating. The ATF can overheat when the ATF cooler function is weak, and/or the transmission, incl. the torque converter, is generating an unusual amount of heat at the higher speeds.

The two lines to the cooler include both metal tubes and rubber hoses. These should be inspected for possible restrictions; e.g., a rubber hose that is collapsing at a tight corner, or a metal tube that's been compressed.
Please help me Sir Master of all Subaru’s!
 
21 - 40 of 54 Posts
Top