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XJ failing inspection -- Readiness

Z

zPike00EB

NAXJA Forum User
Location
Warwick, RI (NEIT)
Hey guys. It's been awhile but I've got back into the XJ world. Got a white 99 with 79k for a steal few weeks back. Needed some exhaust work and tires, but it's otherwise mint.

Brought it for inspection and it failed the OBDII readiness check. The Cat, Emissions, and Evap systems come up as not ready on a reader.

There has been no issue with dead/dying battery, and it has been driven 300 miles since the issue was realized.

I've found a few posts that say just drive it, and other that suggest an issue with the computer.

Any insight?
 
300 miles since the issue was realized...could you clarify what that means?

It is one thing if you discovered that issue 300 miles ago, another if you resolved that issue 300 miles ago.

I went through that issue of readiness tests with my '96. No one had a definite answer for how much driving it takes for the computer to finally get around to running those checks. I suspect part of it may relate to the type of driving. Open freeway driving is one thing, stop and go is another. Getting the right mix of the two may be part of the algorithm.

I would be hesitant to replace the computer. Do that and you know you are all the way back to square one. Keeping the battery live and racking up another 100 miles would be my choice. And don't let them start the test until they first check with a scanner to see if all the readiness tests have been completed.
 
When the computer has been reset (IIRC) there is a minimum of 5 heating and cooling cycles along with a minimum of 100-150 miles of driving before the OBD2 is ready.
 
Worded it strangely -- it has been driven 300 miles since the scan that revealed the sensors were not ready.. And they still show not ready.

Truck has been subjected to different types of driving; highway, city, traffic etc.
 
One thing someone mentioned was also about those heating and cooling cycles.

I noticed that the operating temperature never fully reaches 210 ("noon" on the temperature gauge). Stays half a tick away.

Not sure if this is normal or if it could be causing the XJ to not consider itself at operating temperature and logging a cycle
 
Mine hardly ever reaches that mark.

It has to be a really hot day, working the engine hard and running the AC.

I doubt that is the obstacle.
 
After over 300 miles of driving and more than likely numerous heating and cooling cycles; as others have posted.... the engine temperature gauge not reaching the 210 mark is not the problem.
You may need to connect a scan tool that can read real time to see what is holding the system from reaching a READY state.
 
I'm not sure what the system contains, like I mentioned I haven't had the jeep for very long.

I've put another 100 miles on the jeep -- gonna try and have it scanned again tomorrow.

I'll update as soon as I know.
 
One of my friend's gf's hyundai sonata v6 kept on failing the readiness test. I have an elm-327 wi-fi obd2 tool($20) that I use with my iphone(get the elm-327 blue tooth mini for $10 if you have an android) and spent $6 on the EngineLink app originally to check codes(sold the LM-2). I had his gf pay me $20, so I could buy the NovaScan app, which has readiness monitors and works with the elm-327. She ended up having to drive 60mph for 60mi, no a/c, for her Hyundai to be ready(insane cycle). If you reset codes, you'll have to drive some cycles to get it ready.
b0b1a90c2d8f4432d01807a8bf2544d2.jpg
 
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Update: just had the sensors checked. All three still read "inc".

Rhode Island has now suspended the registration for the vehicle which introduces an entirely new issue: how am I supposed to rack up miles of its not legal to drive?

Any idea what the cycles are for the XJ?
 
I don't know of anything for Jeep but here a couple I found.

Here's a generic instructions -- http://www.aa1car.com/library/us796obd.htm

Here's one for some Chrysler -- http://www.obd2.com/support/reprog/downloads/chrysler/chry-imset_procedure.pdf

Seems pretty clear you need to get operating temperature hot enough to enter closed loop. Fix the temperature problem. On 97+ the single sensor in the thermostat housing provides temperature data to the computer and feeds the gauge. Simple thing would be to get an OBD2 scanner and read the coolant temperature sensor data from the computer--if you see any data then the sensor circuit is working. Then point an IR gun at the thermostat housing and see if the temperature data matches the reading--if so then you are just running cold and need a thermostat, otherwise the sensor is probably bad.
 
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zPike00EB said:
Rhode Island has now suspended the registration for the vehicle which introduces an entirely new issue: how am I supposed to rack up miles of its not legal to drive?
Click to expand...

Do they offer some form of a temporary operating permit?
 
Have you had it scanned by a quality scanner? There can be codes present that done set the check engine light and generic global scanners done pick up. Chrysler drb is the best. But as stated readiness monitors can be a pain to complete
 
*update*

Took the jeep to a friend at the dealer. His scanner showed a P0463 ( fuel sending unit voltage too high ). The gauge HAS been acting up and it currently "stuck" at empty. Not sure if this could cause any type of interference or malfunction. Going to check the grounds/connections and look into replacing the fuel sending unit.
 
You should be able to bring the car to a shop and have them "ready"(or arm) the emissions system.
Could take a long time just driving the vehicle.

Problem, with failing multiple times. I was very worried myself when I had the same issue w/ my '96 FWB. fortunately driving it fixed the "readiness" issue, however I was told by the test facility and the shop I use for tires, a/c and the likes that they can arm the system for me.
Best Luck!
 
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