Suburbman

Our 2003 Suburban with the 5.3L is showing this code. Anyone have any particular experience or knowledge related to this sensor? Would you happen to have a general location drawing showing the placement of this sensor?
Thanks much.

ZX1100F1

This DTC indicates that there is a failure in the heater portion of the heated oxygen sensor (HO2S) the heated element has most likely burned out and is drawing less then a quarter of an amp.

Before replacing a sensor check for any open fuse.

There are two HO2 Sensors bank-1 sensor is just aft of the catalytic converter on the driver side exhaust y-pipe and bank 2 sensor is aft of the catalytic converter on the passenger side.


Without a scan tool it is tricky to determine which sensor is faulty, the best course of action may be to replace both.

Suburbman

Thanks ZX...

I have a borrowed scan tool and it says that this is the O2 sensor heater circuit malfunction on bank 1 sensor 1... another post I found elsewhere indicates that this would be on the driver's side, ahead of the converter. ..
I haven't received my shop manuals yet....would you happen to know where this fuse is located?

Thanks again.

ZX1100F1

My bad, last time I try to go by memory.
Bank 1 sensor 1 is just ahead of the cat on the driver side.

Fuse is location O2A in the underhood fuse box (15-amp).

chelle26

try to check this one..
- - > http://www.bobblick.com/techref/proj.../o2sensor.html
the chevy oxygen sensor is part of the emissions control system. its goal is to help the engine run as efficiently as possible and also to produce as few emissions as possible..it is positioned in the exhaust pipe and can detect rich and lean mixtures and when the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing so your car performs poorly and uses more fuel than it needs to.

Suburbman

Thanks for the input guys...replaced the O2 sensor this weekend and drove the vehicle several times and no MIL..so apparently that took care of it....

The most difficult part of the replacement is trying to get your hands up and onto the connector....the assembly line kinda builds around things sometimes...and this was one of them...laying on the garage floor underneath with a driveshaft in your way kinda hinders things....BUT it can be done.

Thanks to ZX for the fuse check location...it was good.

maxxbear

I have a 2003 Tahoe with a 5.3 fuel flex I have replaced o2 sensor with a Denso sensor my check engin light still comes on its reading code po135heater circuit malfunction bank 1 sensor 1 what else needs to be done?

stripejoe

Check your fuse box in the engine compartment, there are two 15 amp fuses that go to the heated oxygen sensors. Check and see if 1 or both are blown. If so change that and reset codes. If blown that should work, it worked for me. Not many people check those fuses.

Travis Tiny Webb

I have a '02 Tahoe, 5.3L "Z" code(flex). I replaced my o2 sensors with Bosh. When I purchased the sensors, I told the rep I didn't know if the SUV was flex or not. He sold me non-flex sensors that were for my Tahoe, according to dealership part number. I also replaced my heater fuses, which were blown. Now, my truck spews black smoke, my sensors fault codes keep lighting after I reset them, & now my battery(Optima red top) is reading low voltage. I'm a new DIY-er, so HELP!