2004 Transmission Issues (1 Viewer)

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Mine is a 2001. Apparently between 2000-2001, complete transmission failure was a known issue.

Your problem sounds like it’s a sensor issue, as others have discussed.
 
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Updating the thread

Drained the trans again. This time I completely removed the SR and S2 solenoids and tested for their resistance. Both tested at about 13-14 ohms, which is within spec. Reinstalled, and refilled the trans. By now the fluid is like 95% new. Cleared the codes and issue is still there.

I used a wiretap to test the connection between the ECM and the trans harness. Word of warning - I used the pinout from an 02-06 tundra. The ECM's are not the same. This obviously did not work for me, and I lost reverse.

I now have the 04 FSM and will test the pinout using the correct EWD.
 

ramangain

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So slamming into 2nd, still no 5th, and reverse is gone via electrical testing?

Maybe you need to probe the appropriate wires from ECU to tranny on an oscope and capture some traces and compare with another kind soul who can do the same on his/her working rig. You need to rule out that the ECU is or is not sending the appropriate signals, especially if solenoids are testing OK.

I still suspect internals, but opinions are like poop holes, everyone has one.
 
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Eicca

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Did you check ground point EC on the back of the block, passenger side?
 
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So slamming into 2nd, still no 5th, and reverse is gone via electrical testing?

Maybe you need to probe the appropriate wires from ECU to tranny on an oscope and capture some traces and compre with another kind soul who can do the same on his/her working rig. You need to rule out that the ECU is or is not sending the appropriate signals, especially if solenoids are testing OK.

I still suspect internals, but opinions are like poop holes, everyone has one.

Yes, Yes, and Yes. Reverse is back since I disconnected the wiretap.

Here is the 2004 pinout for the landcruiser
1600993805902.png


compared to the 04-06 Tundra with A750f and 2UZ-FE - This was for testing code P0986.
1600993839809.png


When I get back into the garage I will test again with the appropriate wire this time.
Did you check ground point EC on the back of the block, passenger side?

I have not checked this no. I will add this to my list of possibilities, I appreciate it.
 
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I’m having a similar issue with my 2004 Lx When I installed a low miles transmission. Gears 1,2 and 3 come in with a high speed clunk once it gets into the 4 and 5th gear it runs great. Have it at a dealer now. Hopefully they will find out what’s wrong with it. Let me know if you were able to solve the problem, I will do the same.
 
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I just ordered the s2 and sr solenoids since I was running out of things to try. Do you know what codes you had if any?
 
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I just ordered the s2 and sr solenoids since I was running out of things to try. Do you know what codes you had if any?
I have a P0771 code that "sometimes" shows up after code is cleared which is kinda weird. Mechanic is checking all the wiring leading up to the transmission.
 

ramangain

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To the OP: you can also try installing voltage probes on the wires to the solenoids you suspect. If you are half decent at coding, you can buy a little eval board and log the data off of an A/D converter. If you are new to that world, it may take you a bit of time to get up to speed however.
 
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Installed the new S2 and SR solenoids today. No difference. P0986 as soon as I hit 2nd start while in D.
 
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And you verified ground EC is ok?
I looked at the passenger side, and I dont see a ground point on the engine. On the drivers side I do see a ground wire going from the body to the driver side head.
 

Eicca

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I looked at the passenger side, and I dont see a ground point on the engine. On the drivers side I do see a ground wire going from the body to the driver side head.

It’s on the back of the block. You can’t see it without sticking a mirror or your phone down between the block and the firewall. 10mm bolt, should have a lock washer.
 
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It’s on the back of the block. You can’t see it without sticking a mirror or your phone down between the block and the firewall. 10mm bolt, should have a lock washer.

Found it. Seems like its ok, but I also tested the the continuity of the Solenoid at the ECM side and it tested the resistance of within spec. That was before I put in new SR and S2 solenoids
 
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ECM looks fine but according to the FSM it seems like this can be one of the issues?

20201006_145303.jpg
 

ramangain

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Since you have it out, get it flashed to the latest rev. Worth a shot and you may get lucky
 
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ramangain

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My best guess is that the dealer wouldn't touch it unless it was installed in the rig so that can access it through the OBD2 port.

So begins your hunt to find a specialist shop that can do it when the ECU is out of the rig. Most likely a custom benchtop harness is used.
 
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Is that a dealer job? I can only imagine the looks I would get bringing just the ECU to the dealer here.
Take a look at this company.
 

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