Thanks for posting your results. Good info.

It's often the nature of failing resistive heater elements: intermittent. They can open when they're hot or cold or vibrating.

Glad you got it fixed.

 

Testing resistance can be tricky and easy to make mistakes. Was VOM accurately zero'ed or even accurate.

I once measured resistance of secondary on an ignition coil and got a value just over the lower limit. I thought I was good to go. After many frustrating failures to fix the no start, I finally replaced the coil and problem was fixed. I checked my VOM, and thought perhaps I might not have zero'ed accurately, but could not be sure.

good luck

 

I used a digital multimeter and it appeared to be operating properly. However, when I got the OC result, just prior to ordering the new sensor, I did suspect that something was wrong with the way I was doing the measurement. I played around for several minutes trying to figure out what I may be doing wrong but could not come up with anything, so I concluded that what I was seeing was real.

When I took my original resistance reading, the car and sensor were somewhat warm (about 4 hours after using the car). However, when I took the second reading (the OC result) the car had cold soaked overnight. The evenings are starting to go below 50F at night. The third reading on the bench was in a room at 75F.

Thinking that temperature had an effect on the continuity of the sensor, I placed it in the refrigerator and then tested it, but it still registered continuity. I then tried the freezer but still it was OK. Hitting it - OK.

One thing that did strike me about the failure is that the CEL illuminated on the first chilly morning we've had this Fall season, so I believe that there is an excellent chance that the failure was related to ambient temperature conditions.

A bit of a mystery but, at 155,000 miles, not a surprise that a new sensor fixed my problem.