Nissan Repair: Nissan Sentra wont start electrical problem, vehicle speed sensor, nissan sentra

Question
My 96 Nissan Sentra 1.6L will not start.  When the ignition switch is in the ON position, the instrument panel lights specific to the ON position do not turn on.  When the ignition switch is in ACC position, all the accessories and lights work fine, including headlights.  This problem is intermittant, increasing in frequency lately.  It will go away by itself at times.  In this condition, I get three OBDII error codes.  I can connect to the ECM normally with my OBDII software with ingition switch in ON position.  One of the error codes is a VSS reading problem detailed in next paragraph.  The other error codes are fuel system related.

When the car starts without problems, I'm getting one OBDII error code (VSS (vehicle speed sensor) zero reading) intermittantly (every 3 to 7 drive trips).  The speedometer always works.  I've checked the continutity of the VSS signal wire between the ECM (engine control module) and the ASCD connector near the steering wheel, it it checked OK.  I've tested the speed sensor and its OK.  I've cleaned numerous electrical connectors, including the VSS connector, but this does not solve the problem.

I noticed that the VSS connection wires and the starter motor connection wires are in the same wire bundle for most of their length, and that this wire bundle is closest to engine and transmission hot temperatures.

Any suggestions on what's causing the 'no start' and VSS reading problems?

Answer
Scott,

Does the engine turn over?  If not I bet the starter is going out if it has not been replaced lately.  You can check this by jumping a hot wire to the small terminal on the starter when the problem occurs.  If the starter does not turn it is the starter.  Now, if it is an automatic check to see if it will start in neutral.  If so, it is the neutral safety switch and not the starter.  The VSS code you are getting is probably the VSS.  Yes, the thing checks out ok but I have seen this before.  The worst case is you are out some money on the VSS.  If it is the harness where you say it gets hot then you are going to have to cut the harness apart to check every inch of it and that is a pain.  So, take the easy way out.