2002 Dodge Grand Caravan OBD-II I/M Reset Question

Our 2002 Dodge Grand Caravan is due for NJ State Inspection this month, and in keeping with Murphy's legacy, our "check engine" light
decided to appear a week ago. Using the key on-off sequence, the failure code was a P0456, or small evaporative emissions control system leak. Researching the situation, I found reports about this occurring via a loose fitting or failed gas cap. We have been wanting a locking gas cap anyway, so I replaced same, but neither the "check engine" nor the P0456 failure code disappeared after several engine cycles. Not knowing at this point as to whether the problem had been solved or whether the PCM was taking its time resetting, I purchased an Actron 9135 scan tool and reset the P0456 failure code.
After resetting the code, four of the I/M parameters went to "NOT READY" (CATALYST, EVAP SYS, O2 SENSOR, and HO2 SENSOR). After 50+ miles of driving with several engine cold-hot cycles, the "check engine light has not reappeared, and three of the above I/M parameters have gone back to "READY", but the HO2 SENSOR parameter remains at "NOT READY".
Does anyone have any info as to how long this HO2 SENSOR code will take to reset? I have the factory service manual, but can't find any info there. If its going to take 30 or 40 engine cycles to reset, I'll have to just let the car fail inspection, but would rather not go that route if there is anything I can do to get this parameter back in line.
Thanks in advance for any help!
George
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George, That's why you don't do a battery disconnect or reset the check engine lite with a scan tool because it will clear all the monitors that have passed. Each monitor has its own procedures to pass, some actually have to be driven at a certain speed under a certain load such as the EGR valve which is one of the hardest monitor to run. I normally advise the cust to drive it 2 weeks before they bring it back in for a test. It could take more then 40 cycles or less then 5. It all depends on if the engine is driven as the PCM monitor is looking for.
More then likely you have a cracked hose under the vehicle next to the canister or a cracked hose behind the air cleaner housing.
Glenn Beasley Chrysler Tech
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maxpower wrote:

Glenn,
Thanks for your reply to my question!
After I replaced the gas cap, I found myself in a predicament in that I didn't know if or how long it would take the PCM to reset the "check engine" light, or if I had even fixed the problem. The factory service manual didn't provide any quantitative information in that area (or if it did, I missed it).
Is the OBD-II arena such a "black art" in that there are no quantitative definitions as to how each I/M is defined/reset? How do Dodge/Chrysler dealers handle this type of situation on a service call - can the DBM-II/III individually test/reset the failure codes and I/M parameters?
Thank you again for your help!
George
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Normally what some dealers/shop do when they know they fixed the vehicle is to leave the check engine lite on. (some dont clear out the data) The lite will go off on so many good trips depending on what the fault is. By clearing a code or doing a battery disconnect like you did not only erases the fault but it also clears out all montior. Or what is called carb rediness

We can clear codes but that also clears Monitors. do a search or carb readiness. This one I just googled may explain what you are asking. http://www.neons.org/neontsb/TSB/25/250298.htm

1 . Evaporative Leak Detection Monitor - This test will require a cold start (possibly an overnight soak either indoors or out depending on conditions). The ambient (outside) temperature must be between 4' and 32' C (40 and 90 F) with the engine coolant temperature within 6 C (10 F) of ambient/battery temperature. Once the above criteria are met, use the pre-test/monitor test screen on the DRB 111 to determine the remaining requirements. 2. Catalyst Monitor - The vehicle must be driven at highway speeds for the time listed in the pre-test screen. If the vehicle is equipped with a manual transaxle, use fourth gear to help meet the requirements. 3. EGR Monitor - It is necessary to maintain TPS, MAP, and RPM ranges listed in the pre-test screen for this test to complete. 4. 02 Sensor Monitor - The vehicle must be driven and brought to a stop for the time listed in the pre-test screen. Automatic transaxle vehicles must be left in drive during the stop period. 5. Purge Monitor - To see a similar screen format as listed in Figure 1, press the F1 key on the DRB 111 while in the Purge Flow Pre-Test screen. The purge free (PF) cells must update and the monitor will attempt to run on every other throttle closure. Automatic transaxle vehicles must be left in drive for the test to run. If all parameters are met and the test still will not run, place your foot on the brake, open the throttle to 1/4 and then quickly close the throttle. This should allow the PF cells to update. 6. 02 Sensor Heater Monitor - The open throttle time for the 02 Heater pre-test must be exceeded. This monitor will run after the ignition key is switched "Off'. After the DRB 1110 switches to No Response (approximately 3 minutes) turn the ignition key "On" and check the 02 Sensor Heater monitor status. It should have switched to "YES". All other monitors should be completed before running this test.
Rear Wheel Drive
1 . 02 Sensor Heater Monitor - This test will require a cold start (possibly an overnight soak either indoors or outdoors depending on conditions). The ambient (outside) temperature must be between -18 and 38 C (0 and 100 F with the engine coolant temperature within 6 C (10 F) of ambient/battery temperature. Once the above criteria are met, use the pre-test/monitor test screen on the DRB 111 to determine the remaining requirements. 2. Evaporative Leak Detection Monitor - This test will require a cold start (possibly an overnight soak either indoors or outdoors depending on conditions). The ambient (outside) temperature must be between 4 and 32 C (40 and 90 F) with the engine coolant temperature within 6 C (10 F) of ambient/battery temperature. Once the above criteria are met, use the pre-test/monitor test screen on the DRB 111 to determine the remaining requirements. 3. Catalyst Monitor - The vehicle must be driven at highway speeds for the time listed in the pre-test screen. If the vehicle is equipped with a manual transmission, use 4th gear to help meet the requirements. 4. 02 Sensor Monitor - The vehicle must be driven and brought to a stop for the time listed in the pre-test screen. Automatic transmission vehicles must be left in drive during the stop period. 5. Purge Monitor - To see a similar screen format as listed in Figure 1, press the F1 key on the DRB 111 while in the Purge Flow Pre-Test screen. The purge free (PF) cells must update and the monitor will attempt to run on every other throttle closure. Automatic transmission vehicles must be left in drive for the test to run. If all parameters are met and the test will still not run, place your foot on the brake, open the throttle to 1/4 and then quickly close the throttle. This should allow the PF cells to update.

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this may help disconnect the battery on a cold engine let it sit for 2 minutes then start up vehicle.idle and let it reach op. temp then shut it off restart it and drive it like a banshee up to 60 mph then pull off the road and shut it off then do this again and it should reset the monitors or be every close to setting them so the next time u drive it will this is how i was told it could be done thru chryslers odb classes
maxpower wrote:

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