Could it be the Vehicle Speed Sensor?

[rocgalant]

So I attempted to install a stereo in my car today. I purchased the Scosche wiring harness, which I used to connect between the factory harness and stereo harness. That was straightforward. When I turned my car on, the stereo turned on fine, but when I put it in reverse, the car jolted. When I put it in drive, it jolted again. Weird stuff. I figured I should drive a little and see what happens...it's not good. Here's my list of symptoms;
1) Car stays in 2nd or 3rd gear (can't tell cuz the speedometer doesn't work)
2) Speedometer doesn't work
3) Gas gauge literally goes up when I cruise and down when I press the gas
4) Service engine soon light is on
5) SRS (airbag) light is on

I disconnected my negative terminal for 40 mintues and reconnected.
I pulled out my ECU. I checked the fuses in the engine bay and the driver's side fuse box area
I put the old radio back in my car
I visually inspected the wires behind the center console and driver's side fuse area. Everything 'looks' fine. I didn't hear any noises or have any weird odors.

From reading online, it sounds like it may be the vehicle speed sensor causing the issue. Can any of you gurus shed some light on the issue? I really don't want to go to the dealership with my tail between my legs if I can help it.

thanks.

[00galantguy]

You are locked into third gear, a mode often referred to as "limp mode". Id say its almost 90 percent a fuse or a relay. Try switching your headlight relay with the transmission one. If not a fuse or relay could be output speed sensor.

[rocgalant]

Yeah, I checked all the fuses in my engine bay and driver's side door. I don't know how to inspect the relays though. Would I have to pry the relay from it's position to look at it or is there another method?

[00galantguy]

Yeah, I checked all the fuses in my engine bay and driver's side door. I don't know how to inspect the relays though. Would I have to pry the relay from it's position to look at it or is there another method?

Just pull the relay up and switch it with the headlight one. If it works, that was your problem

[00galantguy]

also check the fuse under the dash, 3rd fuse up from the bottom on the left hand side. If that one pops you wont get speedo and will be in limp mode. even if it doesnt appear to be blown replace it anyways, BUT make sure you use a 7.5 amp fuse.

[rocgalant]

also check the fuse under the dash, 3rd fuse up from the bottom on the left hand side. If that one pops you wont get speedo and will be in limp mode. even if it doesnt appear to be blown replace it anyways, BUT make sure you use a 7.5 amp fuse.

I exchanged all the relays in my engine bay. Just basically switched one with the other. I don't know which or where the headlights relay is or transmission relay. Are they in the engine bay? I also changed the fuse in driver's side door that you mentioned (back-up lights in my car). No luck. Thanks for help. Any other ideas?

[minesbroken]

Sounds like an ignition or computer problem. It seems unlikely that you could have done any damage just while putting a radio in unless you did something with that speed sense wire. It could be coincidental. You could check your ignition harness also to make sure all the correct things are "happening"

[rocgalant]

Sounds like an ignition or computer problem. It seems unlikely that you could have done any damage just while putting a radio in unless you did something with that speed sense wire. It could be coincidental. You could check your ignition harness also to make sure all the correct things are "happening"

Minesbroken, you have saved yet another Galant owner potentially hundreds of dollars. I followed your info from the PM and I'm not positive it was a direct result but damnit, my ride is clean again so you get all the credit! I basically disconnected all the connections behind my radio and reconnected them. Quite annoying.

The solution though (I think) was I clipped the yellow/black wire you mentioned on the factory wiring and taped it off. Previously, I didn't think it was an issue because that wire was going to the Scosche wiring harness' orange illumination wire, which I closed off. So the Scosche orange wire was terminated on the harness. Even though the Scosche wire wasn't going to anything, it appears that just having the yellow/black connected to the orange was enough to throw my ish out of wack. Damn I was worried.

[minesbroken]

Thanks man, I always try to help where I can. Anything I can do ;)