Transmission temperature sensor

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klc

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Where is it? I think mine might be a bit off. Sometimes the warning light comes on when I’m climbing a mountain pass. But there has never been any evidence of burnt fluid. I pull over, put it in neutral, and wait for it to go out. The transmission works fine, no jerky-jerkies or heebie-jeebies.

I had the transmission cooler lines replaced in January 2022. I went to Aamco, and they told me to come back in 10k miles for a flush and fill. When I returned, they did not curse me for a fool for burning my fluid. They said everything looked fine, come back in 30k miles for servicing.

I have not discussed the temperature issue with them yet. I did check the fluid again this morning and everything still looks proper.
 

ikuo78

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Regarding 42, there is a description and it is integrated with the transmission range sensor.

It looks like a big job.

It would be nice if the problem could be fixed by simply unplugging the connector and plugging it back in.

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klc

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Regarding 42, there is a description and it is integrated with the transmission range sensor.

It looks like a big job.

It would be nice if the problem could be fixed by simply unplugging the connector and plugging it back in.

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Thanks. I missed that.
 

LibertyTC

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JeepJeepster

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Describe what sort of mountain pass you're going up. Its a well known fact that the 42rle is easy to overheat. If this mountain pass is slow speeds and you're not using 4low, its possible that its just overheating.

The stock aux cooler isn't enough for anything other than normal driving. The towing package (and possibly offroad package) came with a larger transmission cooler. As LibertyTC mentioned above, I noticed cooler temps with the PML pan but installing a larger aux cooler may be cheaper and may be more effective.
 

klc

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Mine’s a Limited, so it’s got the Tow Package. Which is why I’m wondering if the sensor might be a bit out of tolerance. Though I suppose I should make myself buy the larger pan. Then I’ll need to find someone to install it, as I’ve never done anything with transmissions.
 

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I have the PML 42RLE aluminum transmission pan, and changed my external transmission radiator to the bigger one Mopar has "Mopar Service Kit for Heavy Duty Cycle Operation. For Extreme Heat Conditions Only." as they claim (5191979AA I think...), however when climbing a mountain I still have temp issues. So what I did, is I installed a trans temp gauge on the transmission pan (PML can be ordered with the specific location ready) and I watch my trans temps since then.
The funny think is, that my friend who owns a 2008 Wrangler with the same transmission does not have such issues (at least after he added an aftermarket oil cooler). He is always 15-20oC less than I am...
 
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klc

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I need some help, gang, because I’m not exactly in my right mind these days. Where can I find some +12VDC to power the gauge? I was considering splicing into the radio circuit, but I haven’t got my head under the panel just yet. If I’m reading the service manual correctly, a number of things use an orange/brown wire for +12.
 

ikuo78

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In 2003, the left end is B+ and the right end is GND on the larger connector.
I think it's No. 2 that turns on in RUN-ACC.
I think the No. 2 fuse was 10A.
Probably enough.
It might be a good idea to check with a checker just to be sure.


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klc

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Thanks. I need to find that part of the manual.
 

ikuo78

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It should be next to the wiring diagram in the wiring section.
 
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klc

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It should be next to the wiring diagram in the wiring section.
I had not gone far enough into the Wiring chapter to find the Pin Out section. I see it now, thank you again. I’ve thought of replacing the radio as well.
 

KJowner

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Cigarette lighter is probably the easiest thing to get a feed from.
 
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klc

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Cigarette lighter is probably the easiest thing to get a feed from.
The gauge is going in the slot down there, so that’s worth looking at. I have a trim panel removal kit arriving tomorrow.
 

klc

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Now I have a wire for the temp sensor run and stuck down. Already 80 degrees at 9am, and the morning sun was still coming in under the bow. I was stewing in my own juices. I need to get a ring terminal to make a pigtail for the ground wire.
 

klc

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Gauge. Now that I’ve had a look at things I’m going to put a hole in the panel in front of the 4WD handle for a permanent mount.
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klc

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New pan. Trying to block the sunlight in the second shot. I got about fifteen miles on this thing now.
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KJowner

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New pan. Trying to block the sunlight in the second shot. I got about fifteen miles on this thing now.
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Nice, it's a shame nobody sells bits like that in the UK.
 

klc

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It’s hard to read in bright sunlight, but I don’t have to look at it so much. Good for a start.
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