P0135 B1S1

[Kraig]

2006 5.3, 229k miles, upstream O2 sensor heater circuit problem. I replaced the sensor, same problem. I rang the heater circuit wires in the sensor I took out and they were not open, which is I think the typical mode of failure. Fuse is good and if it weren’t, B2S1 would have the same failure. I pulled the fuse box and there is two pink wires coming off the fuse as there should be. The pink wire goes direct to the sensor and the other end of the heater circuit is to the ECM. Before I dig too much further into it tomorrow (it’s dark and time to get ready for bed) has anyone else troubleshoot this problem or know of a common failure point?

 

[afpj]

Did you confirm wires to sensor connector and to ecm are intact electrically? (Ohmed out) . Also did you let engine run enough to let heater circuit run its cycle? Just trying to cover basics