When you have a manual, you can put your hand on the shift lever and (usually) tell what gear you are in. But with an automatic: not so easy. You have four gears, plus lockup in each gear, for 8 different combinations; what gear are you in?

Introducing the Super Duper Automatic Gear Shift Indicator! It displays a two-digit code, from which you can tell the gear. 0-2-4-6 are 1st, 2nd, 3rd, and OD, with 3,5, and 7 representing lock-up in 2nd, 3rd, and OD respectively.



OverDrive with lock-up (close to 7volts)

But wait, there's more!! With key-on, transmission in Park, the Indicator switches to displaying the throttle angle (TPS). At idle it's 0.0, climbing in whole volt steps to 8 at WOT. At any point, if you step on the brake, the indicator drops to 0.0.

This is much better than the "standard" method of checking the TPS, because it tells you what the ECM thinks the TPS is indicating! Plus it's a whole lot easier (especially with a 3VZE, with the connector pointing the wrong way). You get the brake indicator for free.

Is that all it can do? No, there's much, much more! It can tell you the stored Fuel Trim, the O2 sensor output, and even help you (a little) to read the Codes.

You can do all this with your multimeter. Sorta. But it's hard to drive around with your multimeter leads on the diagnostic port. This is just a 12.0v voltmeter module, connected by 4-conductor cable (3 are used, 90in) to crimp-on fork connectors cut in half to plug into the diagnostic connector. (A "pin" connector might have worked better.) Running a cable through the firewall to the cabin is non-trivial, so I just ran it out the hood and through the vent.

Showing the half-fork crimped connector


You just attach the meter to the dashboard with a 3M-brand Instrument Mounting Package.:

Indicator with 3M Mounting Package

The "red" and "black" wires of the voltmeter go to B+ and E1, and the white wire goes to Tt (for gear shift function).

Installed for Gear Shift Function

Too rich for your blood? The meter costs $2.25. Delivered. https://www.aliexpress.com/item/High...354589100.html You can get 10 meters of the four conductor cable for $5. https://www.aliexpress.com/item/10M-...433938726.html

Try it. You won't regret it.

 

I originally had three LEDs connected to the shift and lockup solenoid wires. The on off sequence of the lights told me the gears. Simple, not quite as simple as this though I think.

 

I know, old thread, but this is too cool not to comment on.

That is really awesome scope! I assume it works the same for the 22RE? I'm always wondering which gear/lock up I'm in..

 

It works on the electronic transmissions (like the A340H). Your engine doesn't (entirely) determine which transmission you have. But the transmission is listed on your door pillar.

 

Luckily, I just happen to have an A340H!

So those half forks stay in the Diagnostic box at all times, and the lid just stays open? I guess it would be pretty hard to get any water in there driving around.

I will be ordering one of those Volt meters and doing this for sure. Thanks scope!

 

If you want a more permanent installation you can pick up Tt at the ECM. B+ and E1 are just 12v and ground, and you can grab that anywhere. I wouldn't recommend it, though. The beauty of this setup is that it does so many things. You just need to move the sensor wire.

 

So, this means I can set my TPS on the truck more accurately than trying to set it on the bench with the TB OFF?
I know the TPS effects shift points and if not adjusted properly it seems like you just keep pressing on the gas pedal going up hill with little or no response til it down shifts. But, when set more accurately it will actually accelerate when pushing on the gas pedal while climbing a hill.

 

May I ask one question, scope?

Why did you use those terminals in the test box? The fork terminals cut in half? Or wanted to use a pin terminal? Why not use a spade terminal, which the female terminals in the test box are. They are the female spade terminals.

Male spade terminal.

They fit well, and you can get the 3/16" or 1/4", which is what the picture is, to fit the females exactly. They stay in properly, won't spread the female terminals, give better connections electrically, etc, etc.

I'm just curious, is all, what your thought process on this is.
Pat☺

 

3/16 of an inch? Where do you think your truck was built, Libya? [The US and Libya are the only two countries still officially using the "imperial" system of measurement.]

The OEM male connector has pins that are 2mm (as close as I can easily measure them):

A 3/16 inch blade would be about 4.8mm; much wider. In fact, the female sockets are spaced only 4mm apart

so using even a 3/16" blade would almost certainly short adjacent pins.

There's a reason that our favorite SST is a paperclip.

But to answer your question, I used a half of a fork connector because that is what I had that was close to 2mm.

 

Well, yes, but keep in mind that you are really only setting the "idle switch." Of course, if you're WAY off on the idle switch, the entire sweep of the TPS will be off.

The best reason to use the Tt method is that it is both easier and more reliable for setting the TPS. But you can also look at another parameter that doesn't get mentioned much. If your TPS has been sufficiently beat-up, it could have drop-outs where the resistance doesn't change smoothly from one end of the travel to the other. That could really mess up your shifting. With the "Automatic Gear Shift Indicator," you can watch the TPS walk gracefully through each of the 8 steps as you gently press the accelerator pedal.