Hello - hoping someone can help. Here is the scenario. 94 ES300 190K miles.

The check engine light just came on, at same exact time the O/D light started flashing. Car is not going into top/overdrive gear - other than drives fine.

Actually for couple months the car hasn't been going into overdrive - but initially there was a weird workaround. I could be driving down the highway at 55mph and normally at that speed the car would be in top overdrive gear and rpm's about 2k or just over. But in this state, the rpm's were about 3k. By rotating the headlight stalking to the 1st position (or farther) from OFF, it would immediately drop down to the "right" 2k rpm's. Flip the switch back OFF and rpm's immediately popped back up to 3k (all while driving 55mph - no change in foot pedal).

Then few weeks later i noticed my "workaround" was no longer working...and i couldn't get it to go into the top overdrive gear at all. Then few days later is when the O/D light started flashing (and check engine light popped on and stayed on). Have not had the code checked yet but wondering if others have any ideas.

This car has started getting pretty unreliable the last yr or so (in/out the shop for 1 thing after the next).

 

Wow, that is something I have never heard, manipulating the O/D with the headlight switch.

 

well initially it worked but that trick stopped working pretty quick. i had been thinking it was something in the electrical system like some short or something. but i was looking in a chilton's manual (for camry - since they don't have one for an es300) and in the automatic transaxle section it has a section about o/d light flashing and interpreting the codes - apparently there is a code based on the # of times it flashes, then pauses, etc that might explain it a bit. things like "speed sensors 1, 2" and "shift solenoid 1, 2" seem like possible causes for this...(but i guess for sure the check engine code needs to be pulled)

 

According to the A541E (94 Lexus/Camry) transmission service manual, while driving uphill with cruise control activated, in order to minimize gear shifting and provide smooth cruising, overdrive may be prohibited temporarily in some conditions. The cruise control ECU sends O/D cut signals to the ECM as necessary and the ECM cancels overdrive shifting until these signals are discontinued. Of course, a short or an open in this circuit is just a possibility, but taking into account the weird workaround that you found out, I'd give it a try.

A flashing O/D light means that a Pxxxx code associated to a transmission malfunction is stored in the ECM. With a basic OBDII scanner you will be able to easily pull this four-digit powertrain DTC out.

 

94 is OBD2? thought it was OBD1?... have you service your car recently before this happen?... i remember when i got my car smogged the O/D light was blinking crazy until a little pin was removed from the diagnostic port under the hood.

anywho... its your best bet to pull up the code first.

 

Although the OBD-II interface was not mandatory in the USA until 1996, my 94 Camry XLE has it behind the coin box with the fuses. The interface is OBDII with the old VPW communication protocol.

 

thanks yall. i tried figuring out the code from the o/d light flashing and it just seems to flash on and off at about 1 sec intervals...indefinitely. i couldn't surmise a pattern to it, etc.

does interpreting the meaning of that even matter? (or is it just a matter of go fix whatever the OBD2 scanner tool tells you the code is?)

has anyone replaced things like speed/shift sensors? is it doable for an extreme novice or leave it to the pros?

 

yeah ... i thought so... i figure it was like around 96. i guess it all depends on the car also.

 

yeah it does matter how many times the O/D light blinks. certain pause and blink will tell u what it is. i think theres an owners manual in the forum that u can search for and look for the blink'n codes.


as for speed sensor... i forgot where its located... i remember changing it... just had to be gentle

 

a lot of 94-95 cars were sort of a hybrid obd if u will, I remember my 94' grand prix had an obd2 connector and obd 1 electronics. Just like mikelex said.