Shift Lock ECU, the only part that comes close to calling that is the shift interlock ECU, but that has to do with preventing the transmission from shifting out of park without stepping on the brake pedal.

From what I understand, all functions for the engine and transmission are all control through the powertrain ECU; it process all the sensors and switches input to control the output for fuel control and transmission shifting. If you are having problem with the transmission not shifting to high gear or engage the torque converter clutch (your 5th gear) I would suggest looking into the sensor and switch inputs; coolant temp senor, throttle position sensor, etc.

 

Shift Lock ECU, the only part that comes close to calling that is the shift interlock ECU, but that has to do with preventing the transmission from shifting out of park without stepping on the brake pedal.

Close, but not quite.

There is a Shift Lock Control ECU. P148 of the wiring diagram under the ECT and A/T Indicator

Unfortunately, Toyota calls both the same thing in places. I don't see anything in the mechanical FSM by name about the stuff I noted below. Only shows up in the electrical side with the Shift Lock Control ECU name

Interestingly, on all the tranny pages, there is a note that says: HINT: It is possible to deactivate the electrical shift control by disconnecting the transmission wire. The gear positions can then be changed mechanically with the shift lever.

It is a big connector, looks to be behind the drivers front wheel under the truck, probably 20 wires, connects down into the tranny.

Anyway, I wrote about the shift lock ECU here
http://www.toyotanation.com/forum/6...ion-2005-2015/277377-shift-indicator-d-light-not-working-right.html#post9841914

But follow along to message [URL=http://www.toyotanation.com/forum/usertag.php?do=list&action=hash&hash=1]#1 0[/URL] for a slightly easier way to troubleshoot.


Some notes on no up shift 4 --> 5
1. Transmission control switch circuit (D - 4) *
2. Engine coolant temperature sensor circuit *
3. Speed sensor NT circuit *
4. Shift solenoid valve (SL1) circuit *
5. Shift solenoid valve (SL2) circuit *
6. Shift solenoid valve (SR) circuit *
7. ECM

* Indicates some DTC code should be set. Ask your dealer what code was set, or use a scangauge type tool.

Nowhere do I see an indication that the Shift Lock Control ECU is to be blamed, unless its buried under the generic "circuit", which it could be.

There are various codes buried under #1 , which could be tied to various solenoids failed, which describes which gear it goes into depending on what fails.

Good luck, let us know what codes, if any, were thrown, and we may be able to say more. Have to run to a meeting.

 

Ok well that puts enough doubt in my mind to get a second opinion. My gut feeling tells me something got jacked around when then did the frame replacement but when I took it in they said nope it is the shift lock ECU. There is another Toyota dealership in my area that I will take it into and get a second opinion. This really sucks cause my truck was running flawlessly till that frame replacement.

 

The shift lock control ECU is inside the shifter box, it's not that hard to get to. But it's even easier to test. This is the electronic box that tells the main ECU whether the shifter is in 4 or 5, or 1 or 2. The shift cable only moves through 2, 3 and 4, so the shift lock ECU is needed for the 4-5 shift or the 1-2 shift. So it might make sense that it's bad.


First you have to get inside the console, the top just pries up. There are two connectors to the shift box, a 9-pin that is the park-neutral position switch, and a 12-pin that is to the shift lock ECU. Disconnect that connector, and you will be looking at the ECU pins itself, numbered RIGHT to LEFT and top to bottom. With the key on, test resistance between pins 2 and 9, it should be closed (low resistance) in D and open (high resistance) in 4. Pins 3 and 9 should be opposite; open in D and closed in 4. You can do the same thing with the L-2 shift, pins 5 and 10 should be closed in 2 and open in L, and 4 and 10 should be open in 2 and closed in L.


If you don't get the right result, then you have a bad shift lock ECU. Replacement once you spend the big bucks is not hard, there are two layers of cosmetics to remove from the top, by disengaging some claws, then a pin to remove and a couple more claws and the top of the box comes off. Inside, the ECU is held in by 2 screws, and you save $300.


The only thing that worries me is that I thought a bad shift lock ECU would throw a P0705 trouble code and light the CEL. You didn't mention that. Looking through the FSM, other causes of a failed 4-5 upshift are issues with solenoids SL1, SL2 or SR, which could be caused by damaged wiring during the frame replace, something with the engine temp sensor circuit (tranny won't shift into 5 until the engine is warmed up) or the input shaft speed sensor. Again, those could be from damaged harnesses. But again, I think those issues should throw trouble codes of their own. If none of these are the problem, then the FSM says to suspect the main ECU, but we've rarely found issues with the main ECU in this forum.


Good luck!

PS Sorry for the redundancy, I am apparently a much slower typist than RTFM!

 

PS Sorry for the redundancy, I am apparently a much slower typist than RTFM!

I cut and paste a lot.......

Nice write up, a lot clearer than the writeup I did back in August.

 

Thanks for all the info. To me that makes sense now because this problem did not start till after the frame replacement and if the connector by the front wheel is disconnected or damaged by the Frame being replaced it falls on them. I am not getting any engine lights at all so not sure about the codes. At any rate I am taking it into another Toyota dealership to find out what they say. If they come back with same problem and not related to the frame replacement looks like i am on my own but if they take a look and it is anywhere near the frame I am going right back to the other dealership.

 

So sprede, did you figure out what the problem was with your shifting?

I swore about 18 months ago that I had this problem one day. I was driving on the expressway and noticed the RPM's were much higher than normal...like 2400 when driving 55 mph. After I got off the road and turned off the truck, then restarted a few minutes later it was back to normal. I took the truck in the next day but they couldn't find anything wrong and my scan gauge never registered any code. Now I noticed the truck doing it again, 2 days in a row. I was only on city streets but the RPM's were over 2000 when I was driving 40 mph. I know the truck was not shifting into the highest gear. I've also noticed that on some tanks of gas I'm getting much worse gas mileage than normal so I think I've had the problem intermittently but not noticed since I do a lot of driving on city streets.

As a side note, my P0328 code (knock sensor) has come back and it will not clear. Well, it clears and comes right back again within a few seconds. I've had the knock sensor actually replaced in December 2012 (thread here). The code went away but then came back again occasionally. The next suggestion was to replace the main wiring harness if it became more of a problem. I may have to do that now and I'm wondering if this shifting issue may be related.

 

Just wanted to update this in case someone else comes along with a similar issue. Seems my two problems were related. They found my wires chewed up that were going into two of the knock sensors. After replacing both of the wiring harnesses my check engine light (code 0328) and my shifting problems seem to be fixed. $1600 later I sure hope so! I haven't been out on a highway where I can get up over 55 yet to confirm but they told me it is now proper RPMs.