Hi all! I wonder if anyone can help.. My AUQ 1.8t swap has had a wideband o2 conversion and is running really boggy and jumpy and backfiring. I'm going to replace the sensor tomorrow but thought I'd check the continuity of the wiring tonight and found something I thought was strange. I have the following in my loom.. Wideband loom connector pin 1 > ecu loom connector pin 70 (heated o2 sensor) Wideband loom connector pin 2 > ecu loom connector pin 71 (heated o2 sensor) Wideband loom connector pin 3 > ecu loom connector pins 88, 89, 96, 97 (injectors 1-4??!?!) Wideband loom connector pin 4 > ecu loom connector pin 5 (heated o2 sensor) Wideband loom connector pin 5 > ecu loom connector pin 51 (heated o2 sensor) Wideband loom connector pin 6 > ecu loom connector pin 52 (heated o2 sensor) Why would my O2 wire 3 have continuity with the injector wires? That's not right is it? Where is this wire supposed to go to on the ECU!? From what I've gathered these are the functions of the wires on the actual wideband sensor. Pin 1 - signal wire Pin 2 - no wire! Pin 3 - signal ground Pin 4 - heater - Pin 5 - pump circuit Pin 6 - heater + So the signal ground has continuity with the injectors. Should I be pulling apart my loom and looking for breaks in wires or something!?
This is the schematic. Pin 2 is part of a resistor for sensor calibration. Typical LSU 4.2 pin out is also included.
Yes, because that wire is a 12V supply (as shown above at the bottom of the wiring diagram). The way the injectors and lambda heater work is by having a constant 12V fed to one connection, then the injector or heater is switched on by connecting the other terminal to 0V, usually in a fast-pulsed way to give variable 'on-ness' depending on the ratio of on to off time in the pulse train.
