maxstead

I am wondering if anyone could help guide me the right way on how to proceed?

I recently got a few codes on my '07 Burb. P0056 and P0036 - Bank 1 sensor 1, bank 1 sensor 2.

Upon investigation, had a blown fuse in spot 8. Changed the fuse, all good for a day or so, then it popped again. Tried to measure current at the fuse with my 10A metre, and it was obviously more than that - good spark at the lead of my meter. So, unplugged Sensor 2 (after cat) and re-measured, all good. So, replaced sensor 2 on bank 1 (driver side) and reset codes. All was fine for a few hours, then check engine light on again.

There seems to be a connection between remote start and this issue. When I remote start the truck (factory), it runs for 10 seconds then stops. Then the engine light is on once you get into truck. Check the fuse, and it is blown. It seemed that this was the only time that the code came back and the fuse blew, but it happened once when just regular starting, so I chalked it up to coincidence, but this time, when it happened again, it was just after a remote start. Just thought this might shed some light.

The other thing that recently changed was the addition of a brake controller. I used the blunt-cut wires under the dash that are made for this, and connected the two power wires in the engine bay - nothing more. Pretty straight forward. I did remove the controller while troubleshooting this and had the same result, so I don't think that they are connected.

At $110 a pop for these darn sensors, I am going to go broke replacing them all :-)

Are sensor 1 and sensor 2 wired together? What I am thinking is that maybe the short in the heater circuit is in sensor 1, and when I unplugged sensor 2, the short went away - maybe because they are inter-conected? Maybe it was sensor 1 that needed to be replaced all the time?

Any ideas on where to start would be appreciated.

EinST

P0036 actually means "HO2S Heater Control Circuit (Bank 1 Sensor 2)" and P0056, "(Bank 2 Sensor 2)." The 2's usually get the battery voltage from the same circuit and thus you may have lost on the 50-50 chance. Or, it may be something else, like wiring problem or another component. You need to get a hold of a wiring diagram and be more systematic in your troubleshooting. Did you check the sensor for a short across the heating element (terminal C and D, D gets the PNK wire) before taking it out?

maxstead

That would have been too easy. I used a great tool that goes on the sensor and then connects to the impact gun - they come out like butter - after taking it out, checked for short, and there was nothing (but it did seem to be cross-threaded from factory) had to re-tap hole. Anyway, no short once out, but thought that vibration from impact may have loosened my short :-) Do you know where I could get a diagram of the circuit - I really hope that the two are connected - hence the removal of the short when I disconnected B1S2.

EinST

Have you considered a subscription to ALLDATAdiy.com or eAutoRepair.net? I heard the latter has better wiring diagrams but I don't think you can go wrong with either. I think ALLDATAdiy.com is a better value long term if you can take advantage of the multiple vehicle discount. I obviously am not affiliated with these companies in any way.