did you previously have the check engine light on? disconnect the batt? the emission systems have to go thru several test before the computer is ready. Ask them how many systems are not ready most states let you get away with having one system not ready. must likely is the evap or egr they can take sometime go kick in, thats why they tell you to keep driving. fyi if you disconnect the batt the computer will have to go thru the test again.
Yes to both your questions. After having codes taking care of it was a bad o2 sensor bank 1. 3rd time at inspection NO codes came up. But computer was ready. Drove from Newcastle De. To Philadelphia Pa and it still says computer not ready.
It takes 2 complete drive cycles to have the ECM to test all components and be in the ready mode. Since you didn't pass 5 times, I highly suspect an electrical problem with the ECM/PCM. Somehow, it does not have constant power for its memory therefore, the memory and status clears every time you shut the key off. This would also explain the odd cold idle situation, since the computer would run the engine on the default settings until it can recalibrate, usually 5 to 10 minutes. The first thing to check is all the fuses. Pull them out one at a time and check them with an ohmmeter, clean the blades and reinstall. Do this to both fuse boxes, under hood and rear. In the rear box, fuse 28 marked "spare" is not a spare fuse, it supplies power to the PCM,ECM and TCM. If this fails, it is an electrical issue between the fuse box and ECM. At the ECM connector, remove connector #1 and check for power on pin #20. It is red with a white stripe. If there is no power, splice in a wire with a fuse from the fuse box. If you're not comfortable doing this, return to the test shop and explain the situation of the ECM resetting and if they could do the test with the engine running. If they agree, drive the car for at least an hour and a half (city and highway) and bring it in without shutting it off.
I work at a big supplier of auto parts in the Tri-State area. Took it to 3 well known shops. None of them have even said anything about the ECM. I check the fuses myself none burned out. But that doesn't mean that there's nothing wrong with the ECM. I will defiantly try your way out, but I think I'll just give in and take it to GM/Buick. Their gonna slam me with labor but at least I can get a computer for less then the are going to try and charge me. Maybe I should get it "Flashed" first see if that helps???
did you ask them which systems are ready? before going thru all testing, if the ecm was resetting then all.the system would not be ready. if ots just one or two then the ecm is not resetting. before leaving the car tell them you want to know which one of the systems are not ready. reason why is because you would be driving your car for a whole week and it would still not be ready. it has to.meet specify driving conditions. abd thats why some states allow you to pass with at least one system not ready. as long as your check engine light doesn't come on you should still be ok. DO NOT disconnect the.batt. you are not asking for codes since theyre wont be any. ask for system still testing, you can check yourself if you can get your hands on a scan tool.
I understand C-Los. I'm really thinking the computers just going. DMV says no codes but the computer isn't reading or just isn't ready, keep driving. Goodyear shop said it should have reset by now and there's another issue but they couldn't figure it. No check engine light but low tire pressure. ( slow leak in rear tire no big deal) changed spark plugs and wires new pcv valve.
If it's still showing all monitors not ready then yes maybe the ECM is having issues. I can't do much without actually plugging into the car. I would suggest taking to an electrical shop not just a regular mechanic. You don't want to risk changing the ECM and still have issues due to wiring. Good luck