I have a 2006 Pontiac Vibe, FWD, ~160,000 miles, and am experiencing an intermittent electrical issue which is occurring more frequently over time. Sometimes the car will start up without any issue, but occasionally after the engine starts up the dashboard lights will not be illuminated except for the check engine light; the car will also not be able to shift out of park (unless I press the override button thing to the right of the shifter). The engine code is P0500 - Vehicle Speed Sensor (VSS) circuit DTC Severity 2 of 3 yadda yadda. When I press the override button and shift into drive (because I have to go to work) and start driving away, after several minutes (sometimes longer, like an hour or more), the dashboard lights/AC/everything else will come on spontaneously and start functioning normally, but the check engine light is still on. When I use the scan tool after everything starts working fine, the P0500 code is still there as well as another code - C1241 - Electronic Brake Control Module Ignition On/Start Switch Circuit High Voltage. However, after a few days, all the codes will clear and the check engine light will go off - until it all happens again a few days later. I once was able to use my multimeter to measure the voltage at the battery when this was occurring, and it was less than 13 VDC. After it fixed itself, the voltage was over 14. It is as if the alternator isn't kicking on or working right. Also I did some research online and discovered the engine computer will prioritize critical systems when it has low voltage and shut off non-critical stuff like the instrument cluster and AC, etc. So, last month, after my car died on the highway on the way to work and I had to get it towed back home (thank God I have AAA), figuring the alternator was failing, I replaced both the alternator and the battery (it had the white powder stuff, especially on the positive terminal) and assumed I had solved the problem. However, the problem is back and getting worse again, and the positive terminal on my battery is getting the white powder stuff. What could the issue be?
Well those are always stinkers but what I would do for you would I'd replace the ignition switch electrical part first because it's off in there. If not it could be anything in the wiring. I doubt if there's anything to do with the speed sensor but you never know when things short out they can short all kinds of stuff in the electronic system
