Q: Why does my oxygen sensor heater stay in not ready mode on my 2002 Cadillac Escalade

asked by on January 08, 2017

It's smog time in California and my car has no error codes in the ECU what so ever but no matter how many GM drive cycles I do and cold start idles, the Oxygen Sensor Heater won't go from NOT READY to READY. I have a scanner and this is the only sensor besides the EVAP which is incomplete. Any idea on what do do about this o2 heater.

My car has 281404 miles.
My car has an automatic transmission.

Hello. If you have performed the necessary driver cycles and have not lost battery voltage or reset the computer at any time then you either have a problem with the heater circuit of the sensor or the computer is failing. I usually test the heater circuit first as it will not set a code if it is working, but just not reaching the right temperature. Keep in mind that this does take quite a few drive cycles to complete. If the circuit is fine then the computer should be reflashed and then replaced if it does not take care of it.

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