03-04 TJ input about EATX relay

mrblaine

mrblaine

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I have a mountain of harnesses I am trying to sort through and identify. A couple of them have the PDC so we were using the absence of the EATX Relay to determine if they were auto or manual. Since we just finished a manual to auto swap in Chris's rig, it dawned on us that we did not add an EATX relay or fuse to get his to fire up and run and shift the trans correctly. The EATX relay provides power to the TCM. So, I had him send me a pic of his PDC and sure enough, the relay is there, it was there for the manual and since my electrical genius is out fucking off on his scooter, we didn't have time to figure it out yesterday.

So, any other diagram monkeys want to take a stab at it? What does the EATX relay do when it is in the PDC for a manual trans equipped rig in 03-04?
 
Looking at the wiring diagrams, I don’t see where it does anything in a manual transmission equipped TJ. Fuse 5 in the fuse panel supplies battery voltage to the transmission module pin 56 and cavity A1 of the transmission relay. When the transmission module energizes cavity A2 of the transmission relay battery voltage is sent to pins 16 & 17 of the transmission module and to pin 3 of the transmission solenoid/pressure switch assembly. Maybe someone will see something I’m not.
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50 miles so far with the EATX fuse removed. I can't tell a difference in anything.
 
Agreed that from the diagram, the relay shouldn’t be there unless it came with an automatic. I have an 04 manual without the relay.

Ask Chris to check his build sheet. Could it have been an automatic originally?
 
RMETeeJay said:
Agreed that from the diagram, the relay shouldn’t be there unless it came with an automatic. I have an 04 manual without the relay.

Ask Chris to check his build sheet. Could it have been an automatic originally?
Click to expand...
Not likely since JJVW has the same year range and it was in his as well.
 
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Just checked my 04 manual Rubicon and it has fuse 5 and the transmission relay installed.
 
mrblaine said:
I have a mountain of harnesses I am trying to sort through and identify. A couple of them have the PDC so we were using the absence of the EATX Relay to determine if they were auto or manual. Since we just finished a manual to auto swap in Chris's rig, it dawned on us that we did not add an EATX relay or fuse to get his to fire up and run and shift the trans correctly. The EATX relay provides power to the TCM. So, I had him send me a pic of his PDC and sure enough, the relay is there, it was there for the manual and since my electrical genius is out fucking off on his scooter, we didn't have time to figure it out yesterday.

So, any other diagram monkeys want to take a stab at it? What does the EATX relay do when it is in the PDC for a manual trans equipped rig in 03-04?
Click to expand...
There are 70 mentions of the EATX in the 2004 FSM and it seems every one of them has to do with the 42RLE. It's also the relay that sets the generic P0700 code when the 42RLE has some sort of problem. EATX decodes as
"Electronic automatic transmission controller". It diagnoses as a DTC for the transmission but since I don't believe the NV3550 or NSG370 transmissions set any DTCs so that leaves just the 42RLE or TCM as setting a DTC via the EATX relay.

I found nothing at all in the 2004 FSM indicating the EATX does anything for a manual transmission. Perhaps those harnesses with the EATX relay used in TJs with manual transmissions were used when those without the relay were temporarily unavailable. That's just a guess though.
 
Jamison C said:
@CharlesHS is good with electrical and diagrams as well so maybe he’ll come up with something sooner.
Click to expand...

After looking thru the FSM electrical for the 03-04 I can't see anything the power fuse #5 for the EATX would affect on a TJ with a manual transmission; it appears to be solely for the transmission control relay and module.
The fuse and relay may be set up from the factory so that during vehicle assembly choice can be made for a ECU and transmission installation.
On a Rubicon there may be other components in play.
 
Jerry Bransford said:
There are 70 mentions of the EATX in the 2004 FSM and it seems every one of them has to do with the 42RLE. It's also the relay that sets the generic P0700 code when the 42RLE has some sort of problem. EATX decodes as
"Electronic automatic transmission controller". It diagnoses as a DTC for the transmission but since I don't believe the NV3550 or NSG370 transmissions set any DTCs so that leaves just the 42RLE or TCM as setting a DTC via the EATX relay.

I found nothing at all in the 2004 FSM indicating the EATX does anything for a manual transmission. Perhaps those harnesses with the EATX relay used in TJs with manual transmissions were used when those without the relay were temporarily unavailable. That's just a guess though.
Click to expand...
We understood all of that and none of it wasn't discussed but we all know that Jeep rarely put a relay and fuse terminals in the PDC or under dash fuse block just to install a non functional relay and fuse. If they were using stock, it makes more sense that those two would be pulled even if used with the wrong transmission. We are baffled.
 
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CharlesHS said:
After looking thru the FSM electrical for the 03-04 I can't see anything the power fuse #5 for the EATX would affect on a TJ with a manual transmission; it appears to be solely for the transmission control relay and module.
The fuse and relay may be set up from the factory so that during vehicle assembly choice can be made for a ECU and transmission installation.
On a Rubicon there may be other components in play.
Click to expand...
The conversation we had was pretty dumb. Sorting harnesses. Part number says it is an 04 harness and PDC. Is it a manual or auto? Oh look, there is an EATX fuse and relay, has to be an auto. Then we both looked at each other with very stupid looks on our faces. Did you install the EATX fuse and relay in Chris's rig? No, did you? No. Alright, how is it running the TCM and trans then? Fuck if I know. Hey Chris, send us a pic of your PDC open. Sure enough, EATX fuse and relay are present and apparently functioning. WTF?
 
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