Speedometer still not working... need advice!

[rhillman75]

So far I have replaced the ECU and the cluster on my 97 QX4. The dealer had flashed the ECU but would not tell me anything about the speedo without the $85.00 per hour charge. So what I still get at random is a P0325 (knock sensor code) and still the P0500 (vehicle speed sensor). I have done everyhting except for poulling out the VSS speed sensor since it won't come out easily but the harness is connected. The speedomoter is the only thing not working. The funny thing is that now I have the "OD" (over drive) light flashing 10 -12 times on start up and then it goes away. Is this related?

[Pwnin O'Brien]

Have you tested the VSS wire?

[rhillman75]

I have not checked that yet. I did check the speed sensor harness for continuity and there was none. Although it did give me a resistance reading of .300 ohms (test was done with vehicle off). I am going to try a continuity test between the ECU and the speedometer harness in about an hour. Any thoughts as to the OD light flashing 1-12 times at start up?

[Pwnin O'Brien]

O/D flashing generally indicates transmission safe mode and it may be related to the VSS not functioning, but I can't be certain.

[rhillman75]

Okay... here is what i have. There is continuity between the harness of the speedometer and the ECU, pin 10 on the speedometer (white/blue) and pin 26 of the ECU. However... when i test the VSS wire off the speedometer while it is plugged in the cluster and have the vehicle lifted and running and in drive...i have only 5 volts positive from my meter and it does not gain voltage while the wheels turn faster. Does that sound like the speed sensor is bad? If thats what it sounds like then that is the only part that i have not replaced because i can't get it out. Any thoughts of removing it if thats what you think?

[rhillman75]

Here is an update on the situation. I now have a NEW speed sensor, and as priorly stated, NEW ECU and cluster. There is continuity between the ECU and cluster. The vss wire shows no voltage gain when the vehicle is running and wheels are spinning, and lord behold... I still have no speedo movement. What am I missing???