I was stuck in detour traffic yesterday - switched OFF the overdrive (button on shift lever), drove for a bit and then switched OD back ON (button on shift lever).
I somehow managed to INVERT the OD indicator status light and actual OD status - that is "OD OFF" light was lit and the transmission was in normal mode - switch to "OD ON" (indicator light out) and the transmission was clearly in 3 speed mode (increased rpm for given speed - dropped out of OD)
Stopped, shut off engine, removed key, opened door to simulated "I've gone home" and then restarted - all was back to normal!
I did hit the button twice very quickly to get back into OD mode (though I missed the first time) - hard to believe I "outdrew" the ECU ;-)
My assumption is that hitting the button signals a "change of state" to the ECU, and trips a solenoid in the transmission. I managed to get the solenoid and indicator light out of synch???
It's a common trait and has probably happened or will to all of us at one time. Drove us all nuts unless we'd read about it here first.
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2004 Tundra V8 Limited Access Cab 4X4, Michelin 265/65/R17 LTX-AT2's, Auto Dim Comp/Temp Mirror, Aero Turbine #2525 muffler, Access Roll Up Cover, Optima D31A battery, Multi-Vex adaptive outside mirrors, Eclipse AVN5510 Nav unit and Sirius SIR-ECL1 tuner, as of 10/07 pictures in my photo gallery
If a combo of all these whizz bangs met their claims you'd have to siphon gas out of your tank every second day and sell the excess horsepower on the third????
If your engine doesn't consume ANY oil it will seize???
Some people should not be allowed access to tools without books!!!
I managed to do this just today - or the truck did it to me. If I hadn't read about the problem here earlier this week I would have freaked out! Great thread.
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The Truck: 2003 Tundra Stepside Limited
The Mods: TRD Supercharger, Unichip (. . . removed . . .), Supra Twin Turbo fuel pump, 5.85" Overdrive crank pulley (9 psi), SS Autochrome headers, Flowmaster cat-back, K&N drop-in, Denso Iridium IK22 plugs, Cryo-Frozen Powerslot Rotors, Axxis/PBR Ultimate pads, Stull Billet Grill, Black Headlights, Black/Clear Corners, TRD Boost gague, PLX Wideband O2 sensor / data logging, AFR Dash-mount Gauge, Front 1.5" spacer lift, 1" rear block lift, Hellwig Rear Anti-Sway bar, SOS Rear Disc Conversion, Wet Okole seat covers, Alpine & JL A/V system, Custom dash stereo & guage panel, Secondskin sound dampening, 20" DeModa Authority (black) wheels & 295/45 Toyo Proxes S/Ts
The NEAR Future: A "real" lift kit, "Offroad" tires, Unichip reprogram . . .
The Future: IPT Valve Body mod, HPC Header Coating, Flex-a-Lite electric fans . . .
The Past (Taken Off): SOS 1.5"/3" drop kit, Tokico shocks
AFAIK, the cause is always pushing the OD switch twice in very rapid succession (less than about a second between pushes). The ECU light reacts faster than the transmission so they get out of synch. In theory, another set of two rapid pushes on the switch would reverse the out of synch situation but I've never tried it. Yes, a complete turn off of the ignition switch allows a full reset.
It's very easy to avoid the problem though. First, don't be messing with the OD switch willy-nilly...use it only when you really need to turn OD off. And when you do need to turn it off, give the button one, firm, deliberate push and then give the system time to react before pushing the button again. Once I started following this approach, I've had zero out of synch situations...despite regularly turning off OD to tow a moderately heavy (3800 lb) trailer.
i did it on my '03 and didn't have to restart to get it back right again. I just pressed it twice quickly again. funny thing is i didn't press it twice quickly to make it happen, maybe i just didn't press the button far enough or something.
You guys do know that your torque converter locks up when you hit the "OD off" button. For my Tacoma, which I believe has the same tranny the tundra has, when I turn the OD off, my torque converter locks up in 3rd gear at 50 mph. This is why when you turn it back on your rpms might raise like it's going into a lower gear but it's just the torque converter unlocking.
When I race the 1/4 mile, I leave the OD on until I hit 4600 rpm in 3rd, then I hit the button to turn the OD off right before it would usually shift into OD and the rpms drop a bit and at that point the truck seems to pull it's hardest. Had I raced with the OD off, my rpms would be lower and it doesn't run as fast.
Anyone else managed to do this?
Linear Mode
