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setting the "readiness monitors" not working

18640 Views 7 Replies 4 Participants Last post by  sointense
After 10 yrs., this Frontier is about to drive me crazy. Had to change the alternator about 8 months ago, and have done the drive cycle atleast 8 times to get it to pass emissions.
Have wondered if my ECM is losing it's memory. Had a friend hook it up to his computer today, and it said it couldn't communicate with it. The scanner I have shows 5 readiness monitors not ready. OXYGEN SENSOR MONITOR,

One place I saw said, "If the Oxygen Sensor Heater Monitor is not ready, check to see how many other Monitors are not ready. If the Oxygen Sensor and Catalyst Monitors are also not ready, the most probable cause is a weak battery. If your Battery is 48 months old, replace it and re-run the Drive Cycle. Even though your car may start just fine, the PCM or Power Train Control Module is hyper sensitive to the slightest glitch in the Battery and will suspend the Drive Cycle if it is not happy with any aspect of Battery Performance and/or Charging System performance."
My battery is 5 yrs old, so maybe there is something to it. Will try another battery tomm. If anyone has had the same probs., or any ideas, let me know.

The last 3 times I have tried to do the drive cycle, I have had it on jack stands. So much easier than parking at a spot, and letting it cool down, and being able to do 0-55mph for 5 mins. Not sure if having it jacked up is a good way to do it, but figured it couldn't hurt.

Bought it new, 2000 XE with only 49,860 miles.
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Must be something to the 4+ yr old battery theory. Changed it first thing, and cleaned/checked all my grounds, and for the first time, all but 2 monitors are ready. Heading to the emission place first thing tomm., since they allow my year truck to have 2 not ready, and still pass. Never would have believed an older battery would make a difference. Always started it up good, and ran good. Learn something new everyday.
Just took it through, and it passed just fine! Hope this can help someone else down the line. Was driving me plum crazy...................
So true SDHarleydad, so true...................LOL!
Exactly what my friend said yesterday it reminded him of, when he came to borrow my trailer. Knew I wanted to do it again, before I had to let it down.
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