Toyota Repair: 98 Camry P0500


Question
1998 Camry 4-cylinder automatic ~194,000 | Orlando, FL

Okay, so this is pretty frustrating. To summarize -

In May - Proper shifting goes out when going to drive it in the afternoon (not in garage), speedometer works. P0500 code shows
In May - I replaced vehicle speed sensor
In June - Proper shifting goes out and speedometer goes out when going to drive in the afternoon (not in garage). Turn it off, pull it into the garage, it rains, disconnected the battery to reset the code and it started up and drove with no problem (shift and speedometer). P0500 code shows
In June - Go to drive it in the afternoon (not in the garage) and shifting/speedometer goes out. Park it and pull the negative terminal to reset the code. In the morning it runs fine (shifting and speedometer).
In July - Replaced negative battery terminal as I heard the VSS wire grounds through that and mine was all corroded.

On 7/10 I figured I'd check this again. Every weekday I drive it to work and have no problem. Get to work, park in the garage. Drive it home in the afternoon, no problem. I figure I should check if this is only happening when it sits in the sun. So I let it sit, go out to drive it after a few hours, shifting and speedometer are out. Don't drive enough to throw the code or put the CEL on.

7/11 morning, I go out to see if it's still having a problem, NOPE. Drove it up and down the street forcing it to downshift automatically and accelerating to ensure it's not red-lining. It's working perfectly. Speedometer fine. This morning 7/13 no problems.

This looks like it's due to the heat as it will fix itself after not being in the sun. I don't notice any problems while I drive it 40 minutes every morning/afternoon which I'm sure heats up the engine as well..

Some other things that may or may not be related -

-idle lurches a little bit, the engine can be seen moving in park. At a red light, with the brake pressed down I can sometimes feel it trying to lurch.

-There's a crack in my driver side mirror case, but the mirror motor works fine and I don't think it's shorting out due to the elements.

Answer
Hello,
The lurching is not related to the other problems since it happens when the car is not moving so the speed sensor is not relevant, there are actually two speed sensors, one in the transmission and one in the speedometer, I believe this is where the problem is.
The sensor in the transmission sends a digital signal to the speedometer sensor which then sends this information to the computer, if the sensor in the speedometer fails the signal to the computer is lost, since the computer determines shift points it becomes obvious that there is going to be erratic shifting. My recommendation is to replace the speedometer assembly.