Please help before I send it to the dealer.

[rhillman75]

As I stated earlier the speedometer quit working while I was driving although the other guages work flawlessy still. I bought a NEW head... still didn't work, I bought a NEW ECU... still didn't work, I bought a NEW speed sensor... still didn't work. I have power to the speedometer, I have ground to the speedometer. I have 5 volts with the speedometer working. I have continuity between the ECU, the speedometer, and the speed sensor. The other thing I can't explain is that upon start up... the OD light flashes 10-12 times. From what I understand is that this puts it in safe mode. Can anyone help before I send it to the dealership. I already have over $600.00 in just the parts above.

[Pwnin O'Brien]

So you have replaced the speed sensor, the ECU, and the instrument cluster and you're still having the P0500? That would lead me to believe there is a CAN issue. I'll be honest, I think your best bet is to take it to your local Nissan dealership because they will be able to diagnose a CAN issue much more efficiently with CONSULT II. There are a lot of parts that interface with the CAN system and it could take you a long time before you even figure out which one is causing the issue.

[rhillman75]

Actually after I installed the new speed sensor... the code went away (for 3 days). My problem is that I am not getting any reading from the speedometer. I have followed all the diagnostics for the ECU to speedometer to the speed sensor. I just can't figure out why the speedometer will not show a reading. Is there a relay or something else related that I am missing on the 97 QX4. Could it me in the automatic transmission module since the OD light flashes on start up (10-12 times)?