[I<3Boost]

does anyone know how to find out which wire going into the ecu is for the o2 sensor voltage?:crazy:

thanks joe-

 

[twinautomotive]

strange question....why do you need to know? with decent diagnostic equipment, you can read o2 voltage from the obdII port in real time. I wouldn't go probing in the ecu...nothing good can come from it.

 

[blurm]

strange question....why do you need to know? with decent diagnostic equipment, you can read o2 voltage from the obdII port in real time. I wouldn't go probing in the ecu...nothing good can come from it.

Do you happen to know the voltage that is running to the heater circuit to the very last o2 sensor

i have 3 and the post cat heater wires with ignition key on is only getting .60v …. That can’t be right

 

[Tomvw]

If its a Passat AEB, 12V from fuse #29.
If its a later B5/5.5 Passat, 12V from fuse #34.
But if it is a B5/5.5 Passat it would only have 2 O2 sensors (4 for a V6)

 

[Tomvw]

does anyone know how to find out which wire going into the ecu is for the o2 sensor voltage?:crazy:

thanks joe-

The O2 sensor heater voltage doesn't come from the ECU, it is a direct connection to Fuse #29 or #34.
The other heater connection is grounded by the ECU.
Check the fuse.