Overdrive

Hello -

Just a couple of questions. . ...does your transmission control light for over drive work correctly?

It may be your Transmission control Switch TCS. I have attached info on that.

Transmission Control Switch (TCS)
The transmission control switch (TCS) is a momentary contact switch that allows the driver to cancel operation of 5th (overdrive) gear.
The TCS is located on the end of the selector lever.
When the driver initially presses the TCS a signal is sent to the powertrain control module (PCM) .
The PCM uses the shift solenoids to disengage/disable 5th gear operation and activate the coast clutch.
At the same time the PCM illuminates the transmission control indicator lamp (TCIL) , to notify the driver that 5th gear is canceled.
When the TCS is pressed again, 5th gear operation is enabled, the coast clutch is released and the TCIL is turned off.
Whenever the ignition is cycled (vehicle shut off then started again) the TCS is turned off and 5th gear will be enabled, even if the TCS had been on when the ignition was shut off.

As you see. . ...turning the key off and back on recycles it back to overdrive. . .. . .. . .

You will need a breakout box test equipment to do many of the checks. . ..which I am sure only the dealer has. . ..but. . ..we can check a couple of things.

Remove fuse number 2, 10 amp fuse in the Central Junction Box behind the left side of the dash. With a digital ohm meter check to see if the resistance is less than 5 ohms the fuse should be good. If not replace the fuse and then check to see if you still have the same problem. Since fuses are cheap you might consider just replacing it and then doing the ops check.

Remove the switch and there should be a violet/orange wire. . ..this is your hot wire with key on and a tan/white wire. Measure the voltage with key on at the violet/orange wire and it should be 12 volts. . ...if not. . ...then the fuse is bad or the circuit is bad to the fuse.

If good, I would put your ohm meter across the switch and turn the switch on and off several times to see if it connects properly. . ...if not. . ...replace the switch.

You might ever try jumping the two wires together to see if it works okay then. . ..if it does. . ..again the switch is bad.

Let me know what you find.

Hello -

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Do you happen to know if they checked in "freeze frame/failure records"? Sometimes if it doesnt set a code, it will leave an error message in there, but not in the regular code menu. If you are on a hill, the trans shouldnt shift into OD, depending on the amount of throttle you are using. This sounds like it may be a sticky solenoid, will it do all of this whether or not you are climbing a hill?