Battery Disconnect - Resets - Toyota Nation Forum : Toyota Car and Truck Forums

prico82 · 05-09-2008, 11:03 AM

Hi All,

I have researched this forum on this topic, but can't find exactly what I am looking for.

I have an '02 Camry SE 4 cylinder

I was doing some work on my camry over the weekend which called for disconnecting the battery. I didn't know that disconnecting the battery reset the PCM and affected the idling of the car, etc. The Haynes book confirmed this. I also noticed that the battery disconnect caused my speedometer needle to fall all the way forward past the 140 MPH mark. After a few mins of driving, all was back to normal except the speedometer needle. The needle is still all sitting past the 140 MPH mark. No check engine light, the odometer is working fine, and everything else in dash board is working. Car is running like new.

So i disconnected the battery again so I could take out the dash board and manually move the needle of the speedometer to 0 MPH, as well as check if there is anything wrong. Did it, and then reconnected the battery. Looked at the speedometer, and the needle was once again sitting passed the 140 MPH mark! It moved from where I had set it at 0 mph. What gives? Is there some kind of reset required for the speedometer? Will it fix itself after some more driving time? I have been searching the net and cant find anything.

Any help would be greatly appreciated.

TRD VVTi · 05-09-2008, 11:07 AM

What was the work that you did over the weekend?

prico82 · 05-09-2008, 11:10 AM

All I added was a K & N air intake. No other work. I didn't touch anything else.

TRD VVTi · 05-09-2008, 11:22 AM

I'd have the Toyota dealer look at it. Either the speedometer head is faulty our it's getting a faulty input for some reason. They have a scan tool that can pull up live data and observe what's happening.

You really didn't need to disconnect the battery to install the K&N intake.

prico82 · 05-09-2008, 11:28 AM

Yea, I questioned the disconnect. But I was following instructions and didn't want to goof anything up. It was just the negative part of the battery, and I figured it couldn't hurt.

TRD VVTi · 05-09-2008, 11:33 AM

Quote:

Originally Posted by prico82

Yea, I questioned the disconnect. But I was following instructions and didn't want to goof anything up. It was just the negative part of the battery, and I figured it couldn't hurt.

Disconnected the negative battery cable will reset the ECM but shouldn't cause your problem.

Recheck your work, but I doubt that you caused this situation.