so my abs and parking light began coming on and at the same time my speedo and heat were going out. only happened every now and then so i didnt pay it much attention. next the engine light came on and the speedo went out as well as the heat. the abs light, brake light and even my airbag light are all on now. had the diagnostic done and it said p0500, which was the speed sensor. well i replaced both the rear and the tranny sensors and nothing has changed. checked all fuses and nothing gives. i am stuck and need help. if anyone can explain this to me please do...

 

I think your instrument cluster going out, have you checked or run cluster check?

 

Did not run a cluster check as I blieve the issue is more severe. The tranny is also having a higher shift points. I checked for any noticeable fraying in the wires from the rear diff all the way to the module and nothing noticeably damaged. I think the problem is in the module but just not sure.

 

Need help

 

Corroded pcm harness? Weak ground, failing pcm.

 

I'm not sure how to check if its failing. Nothing look corroded though. When I turn the key to on the engine light blinks 12 times. What does this mean?

 

Pull all your codes and post them

 

Do q cluster check too so we get a better picture. Then do a reset by pulling the battery for a while and see what else pops up again

 

try looking here for p0500 info:
http://www.obd-codes.com/p0500
http://www.engine-light-help.com/speed-sensor.html

You replaced the speed sensor. Did you check the resistance of the new sensor versus the old? Was there any difference? Did you check the resistance of the sensor while it was in the truck (which would include the wiring)?

What year truck and do you have? do you have 2 wheel or 4 wheel ABS?

 

The only code I am getting is p0500. The engine light blinks 12 times when I turn the key. Didn't check the resistance as I don't have the proper tool. The truck is an 02 1500 2wd with the 5.9. I checked all the wiring and there is nothing noticeably wrong all the way to the module. Theshift points are way off, heat does not work but will constantly blow heat even when turned off, abs, parking light, air bag light and engine light on. When it first started happening the abs and parking light would come on, speedo and heat would go out. If I turned the heat off it would go back to normal. Its driving me nuts. Sorry it took a min to reply, I kinda passed out for a min. Long week and its only Wednesday.