Shift issues

[lx470roxs]

Hello all,

I have an issue with my 2001 LX470. When I start my car on the shift column it will light up Park and Reverse, shifting into Drive will only illuminate the Reverse column but I can drive forward only in first gear. Is this shift solenoid? Shift cable? I will say disconnecting the negative terminal of the battery to do a hard reset fixed the problem for about a week but did not work a second time.

Thanks in advance

 

[MongooseGA]

Could be a solenoid. Could be wiring, or the ECM. I'm going through trans issues myself, but on a 2005 5 speed. I may be mistaken but I believe 2001 was the model year with the most documented trans issues. I don't know offhand what the most common issues were for these. It wasn't super common, but of all 100s with trans issues, most were 01 (or maybe 00)

In my case, no codes were thrown on the dash or read by my Scan Gauge. If you have access to TechStream, that was what finally gave me a code to go after.

 

[Malleus]

The problem, anecdotally, that you're referring to was the 2000 overdrive clutch carrier (support assy) bearing failure. That's not the OP's problem.

@lx470roxs, I think you have at least two problems, which may not be related to each other. The first is your indicator; I assume when you say "Reverse column" you mean the gear position indicator on the dash?

The gear position indicator is fed through the engine to transmission harness connector, which is above the transmission, on the driver's side. If you crawl up on top of the engine and look down the firewall, you can see all the connectors between the engine and transmission.

 

[Malleus]

The gear position indicator is connected to the transmission through the neutral safety switch which is on the passenger side of the transmission.

The connector you're concerned with is the large one on the left. The small one on the right is the ATF temp sensor connector.

The Neutral Safety Switch is connected to the manual shift lever.

It's the shaft above my hand. It engages the pawl at the bottom of the photo to put the transmission in PARK, among other things.

 

[Malleus]

If the shift lever assembly, the neutral safety switch or the harness connecting the switch to the engine harness (and then to the dash, through the ECU) is faulty, you get the problem you're describing.

Since you say that disconnecting the battery solved the problem in thpast, I'd bet it's not mechanical. Check the switch and make sure you have a nut on the end of the shaft and that the switch isn't loose on the case. If those are OK, unplug the connector housing from the switch and make sure both are clean inside. If they're not, get a can of CRC QD plastic safe electronic cleaner and spray them both until they are.

If that doesn't solve the problem, do the same at the other end of the harness.

If that doesn't work, you'll have to start tracing the circuit. We'll leave that for a minute, because, based on your description, I think that'll solve one problem.

 

[Malleus]

I need to understand your problem better: you say that you can only drive forward in 1st gear. Do you mean the transmission never shifts into 2nd gear, when the gear shift lever is in the drive position, or that you have to put the shift lever into 1st gear to get the truck to move forward?

The reason I ask is that these are two very different problems, with two very different likely causes.

I will say, though, the electrical connection problem may solve both problems, so try that and let us know what happens.

 

[lx470roxs]

Thanks for the detailed response, I will check those connections! Yes that’s correct. Shifting into drive will move the car forward but will never shift into 2nd gear or above. This appears to be due to the gear indicator believing it’s in reverse and not allowing to shift to 2nd or above. Let me check the connections and report back.

 

[Malleus]

There are two reasons why the transmission won't shift into 2nd:
1) the manual shift lever is actually in 1st and not drive, although the gear position indicator shows it's in drive, or
2) the hydraulic pressure isn't building up in the valve body, which may be due to a number of factors.

The transmission in the 2001 Land Cruiser (A343F) is very similar to the transmission in the 3rd generation 80 series, and is controlled in much the same way. It doesn't have the internal control diagnostic capability that the 2nd generation Land Cruiser transmission (A750F) does. You have to find any problem yourself.

To be clear, the transmission doesn't "know" anything about itself. It's more like your oven than your PC. You give it a command and it does (or tries to) what you commanded. If it can't, the transmission control unit notes the problem and sends a message to you, in the form of a diagnostic error code.

If there is a recorded shift fault, there will be a stored error code. An OBDII reader will show you what this code is. The OBDII port is under the dash, above the accelerator pedal. You need this code to accurately diagnose and solve the problem. The recommended procedures for both finding and resolving the problem(s) are in the service manual, which is in Resources section for free download.

The 100 series service manual is much more complex than the 80 series manuals, or any manuals before them, were. This is due primarily to the fact that Toyota chose to use a computer network, known as a CANBus system, to link all the various sensors and independent computers that control the truck. There are two sections in the service manual; one is the diagnostic section and the other is the transmission section. You need to have both sections in order to properly find and fix your problem(s).

The diagnostic procedures are divided into three parts:
1) electronic problems that can be found and solved while the transmission installed,
2) mechanical problems that can be found and solved while the transmission installed, and
3) mechanical problems that require removal of the transmission to find and fix.

 

[Malleus]

The service manuals in the Resources section are pdfs and can be searched using CTRL+F.

Your focus should be first on the diagnostic section, namely, page DI-161 (to jump directly to this page, use CTRL+F and type DI-161 in the search box):

Your problem is in the matrix listing for the electronic problem s that can be found and fixed while the transmission is installed. The likely causes are listed in the order that Toyota considered most to least likely.

One caveat to using the diagnostic procedures in the service manual: these procedures were written for dealer service technicians working on trucks that were within the production life of the vehicle. This means that problems may arise due to age that were not allowed for in the initial assessment of the operation of the vehicle, simply because it hadn't been on the road for long enough for anyone to actually know what was going to happen when it had accumulated hundreds of thousands of miles.

This probably won't affect you in the case of delayed shifting, but it probably does in the case of the incorrect gear position display. Just something to keep in miond as you work through the problem solving exercise, using the service manual.

 

[Malleus]

One thing the service manual will not tell you to do is clean the harness connections joining any given sensor with its related control computer. The service manual was written assuming (incorrectly) that the entire truck would be in the state it was in when it rolled off the assembly line, namely very clean with no corrosion anywhere. Since this will never be the case for a truck with any use, you need to first get the truck, or at least the area in question, in this state, before you start to diagnose any problems.

This is why I started with identifying the relevant connections in the relevant harness and suggested cleaning them, before I started into the actual problem diagnosis. You also need to note the condition of the connector housings on each end of the harness in question, and the general condition of the harness, before you begin serious detective work. This is also a point the service manual will not address, for the reasons above.

Dealer service technicians are taught all this at work, or in school, so the manuals omit these points.

 

[Malleus]

A couple of things you didn't mention in your problem description:
1) what work has been done recently,
2) how long have you had the shifting problem,
3) what other problems are you having and how long have they been going on.
4) what position is the shift lever in when the gear position indicator on the dash shows it's in "R", but drives forward in 1st? and lastly,
5) can you move the shift lever from 1st to 2nd gear, ignoring the gear position indicator on the dash, and get the transmission into 2nd gear?

 

[Malleus]

Download the manual (it's 21.5MB, so be ready for that) and get an OBDII reader and find the diagnostic trouble code(s), if any.

Any code reader at an auto parts store will do, you do not need the most expensive model you can find. A Bluetooth reader will also work, just be aware that some of the apps (like Torque) will not work with an IPhone.

Report back when you've gotten this far, if you still need help.