: front driver o2 sensor, where do connector wire lead to??

11-27-08, 01:35 PM
hey guys;

I've been hard at work on my caddy as I can't pass smog check to get er registered. A while back, I had a thread here explaining why I had to run new harness wires to both of the crankshaft sensors... turned out the wires had been fried over time and cracked open while being hidden behind the exhaust manifold. My only solution was to build a new wire to the ICM, worked perfect and ended up buying 2 new ckp's for nothing =( Here is my old post with pictures of the fried wires and the new ones I made: http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/139996-p1350-p1375-codes.html

Well, as of now, I'm getting engine code P1153 causing the MIL preventing me from passing smog check. I went through diag yesterday and finally ended up that yet again, down in similar location, the wires are crossed somewhere, but I can't find where they are exposed to each other.

Here is problem, If I take off Connector C2 from the ICM and touch both connectors to check for resistance, even after I disconnect the 02 sensor. I even snipped the 4 wires connecting to the 02 sensor connection, but there was still a short somewhere. The short is most likely hidden somewhere in the wire harness. there is 0 resistance, one circuit. :helpless:

Down at the 02 sensor, there are 4 wires on the sensor. Two of the wires head directly to connector C2, from what I gather, the other 2 go to the PCM, but can't find in the manual where they go. The schematic for the "Heated Oxygen Sensor (h02S) Bank 1 Sensor 3" shows the two connectors using circuit numbers 1671 & 1670. I checked the PCM diagrams in FSM (as another diagram shows they might be going to PCM but I'm not certain) and I can't find reference to these Circuit ID's anywhere.

Anyone know where those 2 wires head to? My solution to the problem is I'm making a fresh set of wire harness, but need to know where to connect these 2 rogue wires coming off the O2 sensor. The FSM calls them Pin A & B.