At waht transmission temp does P0218 come up?

[jja]

I am getting the P0218 for the second time after some light offroading. It disappears after a couple of days of road usage.

The second time I checked out the trans fluid temp at the end of the trail and it was around 200. However, the P0218 appeared at some point on that trail (I didn't look at the temp while driving). It was a short trip barely 15 minutes and there has been no wheel spinning, low range engaging or anything like that. Just slow driving uphill on a dirt road.

I have the factory trans cooler and the additional fan installed.

Two things bother me now.

1. At what temp does P0218 show up? Was the trans oil overheated? Do I have to change it?
2. How come the transmission gets so hot with such light usage? Is it a design flaw? How would the truck be capable of doing some more serious offroading without overheating the trans?

 

[LibertyTC]

Turn off Overdrive to stop trans from roaming helps.
Many things have to work well to avoid the trans temp light.
One is fresh ATF+4 fluid, and an overall working, healthy rad cooling system.
Off the top of my head, the trans temp light will activate when it's darn hot around 240F.
Anytime you activate the light, you should consider having the dealer replace filter & use their recirculating machine to install new ATF+4 fluid.
I used to have trans temp lights off road especially in summer, and since I installed a PML 1.5 quart over stock, aluminum trans pan, light has not come on since.
The PML pan includes a drain plug, which assists in draining pan for a refills.
Still, consider have the dealer service the transmission.

 

[jja]

Oh I never got the dash light on. I just read the P0218 error with my OBDII code scanner. So, I wonder what's the severity of this condition.

There has not been any trans roaming either. For most of the trip it was just 1st gear engaged. Also, I changed the ATF like 6 months ago and overall the truck has 50000 miles on it. So, it's not really wear and bad maintenance causing this.

It really looks like design flaw on Chrysler's side. I still can't believe though such a critical component would be designed in such a way that a walk in the park would mean borderline operating conditions. Yeah I am pretty sure the PML pan would help resolve this but heck shouldn't it have been installed in the factory?

 

[tjkj2002]

When your offroad put the transfer case in low range,your auto trans and engine will love you more and able to cope with the heat created much better.


I off hand do not know the actual temp that code sets but 200 degrees in the trans will toast that fluid fast and you must flush the trans ASAP,not a pan drop either but a full flush.

 

[jja]

I off hand do not know the actual temp that code sets but 200 degrees in the trans will toast that fluid fast and you must flush the trans ASAP,not a pan drop either but a full flush.

I am also thinking that is very likely to be the case.

What really bothers me is that the dash light never came on. It was sheer luck that I did the OBDII scan in this very moment. Why would the truck never warn me about it if it was a critical condition? I mean that's what the dash lights are for. So it's either bad design on Chrysler's side or this is considered normal operation but maybe close to borderline and the error code appears just for informational purposes.

 

[tjkj2002]

I am also thinking that is very likely to be the case.

What really bothers me is that the dash light never came on. It was sheer luck that I did the OBDII scan in this very moment. Why would the truck never warn me about it if it was a critical condition? I mean that's what the dash lights are for. So it's either bad design on Chrysler's side or this is considered normal operation but maybe close to borderline and the error code appears just for informational purposes.

Some codes will set but not turn on the MIL(or temp warning light) until the condition that originally set the code repeats itself on 2 separate drive cycles.Some codes are just "pending" as they have not met the required time or number of faults to turn on a light.


This is not just a issue with Chrysler but all makes and models that use OBDII.

 

[renegade 04]

Also If you overheated the transmission you may have overheated the engine as well because the temperature gauge will stay in the middle even if the jeep is overheating, I know this because I have a aftermarket temperature gauge with a digital read out and have seen my jeep get close to overheating and the stock temperature gauge still in the middle.

 

[LibertyTC]

Ya I keep an eye on scan gauge coolant temps as well.
Last time I had a trans temp light it was 85F outside, had been climbing quite a while in 4 Lo, and I pulled over & lifted the hood to evacuate heat & and waited til light went off.
Then gave her 20 min break, with engine off.
This is from the owners manual.
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I change the trans fluid every 30 k now. Dealer does my flushes too.

 

[renegade 04]

The transmission light comes on at 240F and by then your transmission is shoot because you have just cooked the internals.

 

[jja]

Thanks for the input guys.

I found some info in the service manual. Apparently P0218 comes up at 240F. The Trans Temp light comes up at 275F.

There is no recommendation to take any actions when one gets P0218. It is more of an informative message to the technicians servicing the vehicle that the usage conditions/driving style might require additional trans cooler being installed.

The funny thing is there is no recommendation to take any maintenance action when the trans temp light comes on, too. As it says in the LibertyTC post you just stop and switch to neutral with engine running till the light goes off. No fluid change is recommended or anything.

 

[LibertyTC]

Flash point of atf+4 is way way above 240F. LINK: Mobil ATF+4
If you keep driving with the light on, yes you could do damage.
It is the friction modifiers in the ATF that lubricates, and have suffered because of the heat.
That is why a flush of new fluid is required if you have Trans temp light.
My transmission is fine, no cooked internals, just have to be aware of conditions and fresh fluid requirements.

 

[CactusJacked]

Not advocating any product, it was just a handy chart.

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