Mechanics

WHAT IS CAUSING MY BACKUP LIGHTS TO NOT WORK, AND SOMETIMES MY OTHER GEARS DO NOT "RECEIVE" THAT THEY ARE BEING USED?

1994 Toyota Camry • 123,000 miles

Okay. This has been an ongoing and VERY obnoxious issue with my car, and I cannot figure out what is causing the problem! I have heard different "opinions" from auto mechanics about what it could possibly be, but I want to ask someone that will HEAR OUT EVERY DETAIL OF WHAT IS GOING ON AND GIVE ME A REALLY POSITIVE ANSWER!

What happens is when you start the car & PUT IT IN REVERSE, the backup lights do not come on, and simultaneously, the orange "R" (reverse gear indicator light on the dashboard) does NOT come on. At the EXACT same time that this light decides to come on (I MUST jiggle the gearshift handle around for a LENGTHY amount of time, before it will BARELY start making contact. Usually, to get my backup lights to STAY on, I have to apply a little bit of pressure to the gearshift handle towards the "neutral" slot [without putting it in neutral] to make it work), my backup lights SIMULTANEOUSLY WORK! This, alone, causes me to believe I have some sort of connectivity issue, but I don't know what or where it is.

Now, at the same time, when I am having all these issues with my reverse function on my car, the "neutral" light seems to reliably work for the most part without a problem (there is no real problem in that gear), but sometimes, this problem occurs with the "Drive" gear as well. It does not cause any functionality issues with the car, but the "D" on the dashboard does not light up at times, and again, I usually end up having to "lean" the gearshift handle back a little ways to get the light to come on.

Now, for a SERIOUS issue that is ALL related to the above: if I put my gearshift in the "2" slot, and the "2" on my dashboard does NOT come on, my car WILL NOT GO INTO SECOND GEAR. The fraction of a second that the light DOES come on, the car will shift into second gear. As SOON as the light goes back off, though, the car will shift back into third AND NEVER FOURTH WHILE THE GEARSHIFT IS IN THE "2" POSITION.

THIS HOLDS THE MOST CONCERN, THOUGH: when I shift down to the "L" slot, THAT LIGHT ON THE DASHBOARD MUST COME ON, OR WEIRD CRAP HAPPENS! If I take my foot off of both the accelerator pedal and brake pedal, and that "L" light does not come on when I shift down, the car WILL SHIFT INTO FIRST GEAR NO MATTER HOW FAST I'M GOING. I discovered this because I know my "L" gear only shifts down below 35 MPH (NORMALLY, THAT IS!). Well, I was going about 40 MPH, I put it down into "L" (I was slowing down gradually), and WITHOUT MY EXPECTATION, THE CAR JUST SHIFTED ALL ON ITS OWN. As soon as I applied the gas pedal, though, the car shifted back into second, and commenced to shift AGAIN down into first gear, and back into second again! Then, if the gearshift handle is in the "L" position, and the car is going LESS THAN 35 MPH, when that dashboard light DOES come on, the car will briefly shift into second gear, and stay in first gear after that, PROVIDED THE LIGHT STAYS ON.

On a brief side note, the overdrive switch occasionally will not do anything when I push it. I have to push it in again, and push it back out again, and it will usually work after that. Connectivity issue, of some sort, I assume. Again, I'm not an expert, I'm just guessing.

As you know, I have a 1994 Toyota Camry. When this particular problem occurs, it is when the car has NOT been used very much. If the car is CONSTANTLY being used, after about 25 miles of driving, the problem almost totally disappears. If I go in and out of about 20 parking spaces in a parking lot (parking, reversing, and driving each time), the problem would just about fix itself, BUT ONLY FOR A VERY SHORT TIME, IF I DON'T KEEP THE CAR RUNNING. After leaving the car off for about ten minutes, the connectivity has already "degraded" considerably, and I usually end up having to jiggle that handle to make my backup lights come on. If I leave the car parked for an hour, that's even worse. Everything is just like the car just got started for the day.

THIS TOOK ME A WHILE TO TYPE. I hope you take as much time reading this as I did typing it, because I WANT MY PROBLEM FIXED.
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Allen1350
May 31, 2012.



There's two things to suspect. The backup light switch is relatively inexpensive at about $25.00 and could be intermittent.

The neutral safety switch has a transmission range sensor built in and is fairly expensive. There is likely a computer involved with running the lights on the dash but given the description of the symptoms, I'd be looking at that sensor first. You'll need to find a mechanic who specializes in electrical diagnostics to test the operation of the sensor. The alternative is to just toss in a new sensor and hope that solves it but that is not how we like to find problems, especially when the part is so expensive.

Also, I got dizzy trying to follow your shifting description but you shouldn't be downshifting manually when slowing down except in unusual circumstances. The transmission operates differently when it downshifts by itself and it protect itself from undue stresses and engine over-speed. Your observations however, if done when the car is standing still, further points to the range sensor. There's too many different but related symptoms to suggest corroded wiring or connections. That's where testing of the sensor will show if it's intermittent.

Caradiodoc
May 31, 2012.
Doc, I got side-tracked half way-I was gonna give the BU switch and the TRS to check and test but you came in with the silver bullet-Good Job-Always nice to have an electronic doctor in the house. As for me I'm old, obsolete and superseded-much obliged compadre

Rasmataz
May 31, 2012.
Thank you so much for your answers. I'll take the suggestions deeply into consideration. Any other answers are appreciated, to those else who read this!

Tiny
Allen1350
May 31, 2012.
Check the gear shift cable and range switch. Try adjusting them first.

KHLow2008
May 31, 2012.