Another day, another problem. Every engine light on my Dashboard came on last night.

jmontanus said:

2004 LE. The code came up 0500 left rear speed sensor. So I'm assuming that it temporarily disabled VSC, TRAC and ABS, but why the tire pressure warning light? Also, as I kept driving for awhile, the brake warning light came on. I checked the brake fluid levels, they are ok. As is my tire pressure. I just had new pads and rotors installed and the calipers serviced, with only a couple hundred miles since the service. Could the mechanic have accidentally done something to cause this? Can I keep driving it like this? I have a bunch of long road trips coming up this summer that I want to do, but the various problems I've been having lately are starting to really suck.

I long for the days that Toyota's would go on forever with little to no problems, like in the 90's. Less sensors and computerization, which are all the problems I've been having lately.

Here is the photo of the current dash:

Click to expand...

All the lights come on because the early Gen2 Siennas have fairly simplistic symptoms. The TPMS comes on because tire pressure is based off the Wheel Speed Sensor (WSS) data. When one WSS gives totally different data, it assumes the wheel is low on air, giving it a different diameter. Erroneous data from the WSS makes it impossible for the computer to compensate for the ABS/Trac system, so those lights come on. The MIL comes on because there's a code. And the BRAKE comes on because the ABS system is disengaged. Can you drive like this for an extended period? Sure. I did for about 4 months. But I was only driving in-town suburban roads and encountered NO emergency situations. However, it's trivial to solve the issue. Just replace the rear hub/sensor assembly. If you don't live in the rust belt, it's probably an hour of labor. If you DO live in the rust belt, it might add an hour, if you DIY. If you pay someone to do it, it'll probably be a $300-400 job, at most, and may be even less. And it will almost certainly fix all your issues and lights and give you peace of mind for your long trips.

One thing I am confused about, though, is your assertion of the code. C500 is a Front Left Wheel Speed Sensor. P0500 is a Vehicle Speed Sensor A. You left off the leading letter for the code, so I don't know which it is, but neither version of the code suggests a left-rear sensor. If it's the left FRONT wheel speed sensor, it's like a 10 minute job and a $100 sensor.