So, I just did some testing today. I checked the voltage at the ECU with a test probes. I am getting .44 volts on 2 of the wires and 12 volts on the other wire. So I know there is a signal getting to that point. I have a feeling something is wrong with the ECU. I am going to swap o2's again and get a new one to double check. If that doesn't work, I guess I am on the hunt for a ECU/BCU combo, as I am not going to the dealer. I here you need one that is compatible with SAI. Is this correct?

 

Those voltages are fine if the sensor is plugged in.

If you have an Sai vehicle then yes you need an ecu, bcu, and cluster from another 99-04 vehicle.

 

Thanks! The sensor was plugged in.


Do I really have to have a new cluster? I've read it is ECU/BCU digital "handshake" between the two that is the issue. If you are swapping from the 4.6, or vise versa, I saw that the cluster is needed.

 

The cluster has to communicate with the bcu and I believe they also need to shake hands. If they don't then I believe the vehicle will run and drive but the cluster will be inoperable. The mileage is also stored on both the cluster and the bcu so I think that is part of the problem

 

BTW. Did you test voltage at the ecu with the vehicle running? After 10-20 minutes of idling the voltage on one of those half volt wires should have been fluctuating, if only a little. If that's not the case then you have a bad sensor not an ecu.

It sounds like you just tested with the key on which doesnt really tell you anything definitive. Warm it up and do the same test again