First off I would like to thank all you for any insight that I get. This truck belongs to a friend of mine and I have performed the code flow chart for P0037. This is the second time the O2 heater has failed. and some history on this is before I got in involved the O2 had been replace twice. I had replaced it a few months back and now it has failed again. I have searched for TSB's and found the recall G30, but according to the production date it does not apply. I looked for the PCM software version and I has been updated to 62350435AZ. I do not know if it is the right one, nor do I know what the original version was. I have also found another Recall notice, but not sure if it applies to this truck, it is J35 and it is for updated regeneration strategy.

Wiring and basics check out okay and I am thinking it is the O2 sensor module causing the repeated O2 failures. If it is, is this a recall.

Terrence De Waal
Educator/Instructor
Advanced Training Institute (ATI)
Las Vegas, Nevada, USA