O2 sensor is in self-test mode?

[Grt_Ape]

Took my 2006 LJR to get smogged today. Mechanic is a friend and hooked up an OBDII scanner before running smog test.
No codes, but says an o2 sensor is in self-test mode (not specified which one) and vehicle will not pass smog in this condition.
Followed advice to drive on fwy for 5 min, let cool down a bit then bring back. Same info.
Says to let sit overnight, then start and let idle to temp and check again to go through cold cycle.
Thoughts?
48,037 miles

 

[Grt_Ape]

I/M Readiness test on OBDII scanner says o2 Sensor heater. INC.

Took my 2006 LJR to get smogged today. Mechanic is a friend and hooked up an OBDII scanner before running smog test.
No codes, but says an o2 sensor is in self-test mode (not specified which one) and vehicle will not pass smog in this condition.
Followed advice to drive on fwy for 5 min, let cool down a bit then bring back. Same info.
Says to let sit overnight, then start and let idle to temp and check again to go through cold cycle.
Thoughts?
48,037 miles

 

[Chris]

Is it throwing any CEL codes indicating one of the O2 sensors might be bad?

 

[Grt_Ape]

Is it throwing any CEL codes indicating one of the O2 sensors might be bad?

No codes on scanner, and if I key on / off 3 times the odometer only shows "dONe" with no codes there either.
But if I key on without starting the engine, the MIL flashes. This is consistent with the scanner indicating o2 sensor I/M readiness failure.

Further research has led me to believe my issues fall in line with TSB #25-001-07. I guess it is a common issue with the 05-06 TJs. "Before 05-06 they were on their own relay. If you can't find a relay for it under the hood it has been added to the ASD/FP relay."

Going to contact dealership in the morning to see if the repair is covered under lifetime emissions warranty, or if I am doing the repair myself. Just glad I went early on to get my smog check and discovered the issue. That and for resources online here and elsewhere to figure out what's going on and what to do about it..

 

[Chris]

No codes on scanner, and if I key on / off 3 times the odometer only shows "dONe" with no codes there either.
But if I key on without starting the engine, the MIL flashes. This is consistent with the scanner indicating o2 sensor I/M readiness failure.

Further research has led me to believe my issues fall in line with TSB #25-001-07. I guess it is a common issue with the 05-06 TJs. "Before 05-06 they were on their own relay. If you can't find a relay for it under the hood it has been added to the ASD/FP relay."

Going to contact dealership in the morning to see if the repair is covered under lifetime emissions warranty, or if I am doing the repair myself. Just glad I went early on to get my smog check and discovered the issue. That and for resources online here and elsewhere to figure out what's going on and what to do about it..

I think you’re dead on with the TSB thing as that would have been my next suggestion. Let me know what the dealership ends up saying. My understanding is that they have to honor something like this for life, since it’s emission related.

 

[Grt_Ape]

So, FYI....local dealership did the TSB repair at no cost. Got to love that.

Still waiting for the I/M readyness to clear. Says it can take a few days of normal driving cycles. 1 down...

 

[Chris]

So, FYI....local dealership did the TSB repair at no cost. Got to love that.

Still waiting for the I/M readyness to clear. Says it can take a few days of normal driving cycles. 1 down...

Yes, it can take a few days and driving cycles, that's completely normal.

Good to hear that the dealership fixed it for you. Since it's emissions related, I think they really have no choice.

Thanks for the update!

 

[Grt_Ape]

I/M readiness cleared. Ready to smog!