coupeguy2001

A couple of weeks ago, I went to the emissions testing station with my 01 MN6 car. I had spent a few quality minutes in my garage before going there with the car, reviewing codes and resetting them.
Then I gave it no thought, and drove to the emissions station, and they turned on the car and said that the computer was not ready to be tested.
I apparently reset the computer after I had started it with a bad battery after sitting in the garage for about 3 minutes with the ignition on, and no alternator running..When I started it, I got a charge fault message, and it quickly went out. I figured I had drained the battery a little, testing the codes, and the computer picked up on a low battery.
I discovered the real battery issue at the testing station when it was hard to start at the testing station.
I went home, then got a new battery for it, and installed the battery.
I drove the car for about 30 minutes
I checked the codes, and I had an evap and catalyst "not ready" indication.
I had looked up drive cycle on the computer, and then followed the evap and catalyst reset procedures, and still couldn't get them to reset.
I think the problem is the outside temperature. The garage ambient temp is about 105, and I don't think that qualifies as starting the car "cold".
The car sat over the weekend, and Monday morning, I got the steering column lock fail message, and the car would not go faster than 2 mph. after working Monday and Tuesday, I spent yesterday getting the car to run.
I have been working getting the steering lock to work, and today, i have been driving the car to get the computer to reset only I still have the evap and catalyst still not resetting in order to retest the car.
Does anybody have a sure fire method to get these two parameters to reset?
The OBDII drive cycle does not seem to get these two things reset. It's 95 degrees right now and not sure how I am going to actually get the car "cold".

phil hunter

I went through a very similar issue a couple of years back when I replaced the battery a couple of months before emissions testing. Took me over 500 miles of driving to finally get the "Evap" to reset. I must have completed the GM drive cycle at lest 50 times without result. I purchased one of those 9v memory devices that plug into the cigarette lighter outlet. Don't know if it will actually work, but never want to deal with this again.
Good luck.

Phil

coupeguy2001

ttt

GUSTO14

A friend deployed over seas for a year and left his 2001 Corvette in the garage on blocks so the wife wouldn't need to bother with it. We removed the battery and I brought it to my garage where I planned to put it on a battery minder once or twice a month.

Six months later she receives a letter from the NCDMV telling her the car must be inspected within 30 days or she will have to pay a penalty. (Since the car was in both of their names, the state could not exempt it for him being deployed.) She contacted me and ask what she should do. I told her no problem, I'll bring the battery over and drive the car to the inspection site and get it inspected.

At the inspection site I was told the computer is not ready for testing. They told me to drive it around for about 50 miles and bring it back. I put almost a hundred miles on it and took it back the next day. Everything was fine and it passed. I hadn't cleared any codes, just reconnected the battery. Then again I also didn't have a CEL or any other warning showing either.

Good luck... GUSTO

lane_viper

This one is for BMW, but seems to work for other cars. May be helpful. In order to get the Air pump in the O2 efficiency, the engine must have a Cold start.

Bill Curlee

ABSOLUTY CORRECT!

jjc508520

I have an '02 4runner with about 245k miles on it. The design of the emissions system is the only weak link in this otherwise bulletproof SUV. I used to be able to turn off the dash lights using a laptop program (PCM Scan) but here in NJ they have upped their game - after doing this (as I did successfully in years past) their computers now read "computer not ready for testing" and they failed me (the same as you get with a recently-disconnected battery). After a "vigorous" MAF cleaning I turned the lights off again using the laptop and after about a week they did not come back on - so I ran to the station and got my green sticker. About a week after that the lights came back on - I guess I hit the sweet spot where "computer was ready for testing" but the check engine lights had not yet tripped. The cost to fix this emissions problem "the right way" could force me to give up on it and get a new one - don't feel like taking it to the dealer and emptying my wallet on it....

coupeguy2001

Sunday, I took the car out and drove it for two hours, completing yet 3 more drive cycles.
When I got home and plugged in my scanner, it said readiness tests not completed.
I have been driving it to work, and no codes. nothing.
Car drives great and is fun to drive. Just do not want to waste the car performing drive cycles.......That's no fun.
I think the problem might be that the ambient temperature in Arizona does not get below 95 right now, and I can't get it to do the evap on a cold start.
In the mean time, my registration has expired.
Maybe I will have to drive to the mountains near Flagstaff and let it sit for a few hours in 50 degrees, and see what happens.

lionelhutz

FYI, clearing codes will clear the emissions monitors. A low battery or battery connection problems could also cause the monitors to reset.

Here is the Corvette specific info for each monitor you're having trouble with. I see no reason the catalyst won't set if you've driven it off idle for enough time. But, the EVAP could be troublesome in very hot weather.

tblu92

Drive cycles in a 15 year old car can be sometimes impossible to get the readiness tests to read "ready" on all of them----2 years ago they would pass a car with 2 readiness tests reading not ready---1 year ago it was reduced to having only 1 not ready then as of Jan 2016 it was again lowered to "0" meaning all of them must read ready---
Even though there may be nothing wrong with your car and all the emissions are working perfectly those pesky tests can have a mind of their own
If you feel there is nothing wrong with your engine--and have NO CODES sometimes the only way to get all the tests to read ready is to cheat a little
Any tuner with HP or EFILIVE can set ALL your readiness tests to read READY instantly and permanently !!!!---- with a dozen or so key strokes-----This sometimes is your only option--

coupeguy2001

drove it for another week, performed 3 more drive cycles, took it to the testing station, and it passed.
Only thing that helped was we had a storm go through, and it cooled down lower than 100 degrees.

My 86 is on collector car insurance, and no more smog checks.
383 TPI, true dual exhaust, bullet cats, 2002 front brakes, 4 18 inch 2002 thinspoke wheels, and 96 collector edition seats.
now it's plastic interior is just deteriorating. Can't keep it together........

QCVette

Glad it passed.

I hated the emission tests in Phoenix (Mesa) when I lived there. They even damaged my '85 Corvette by missing the tailpipe and shoving the probe into the paint on the bumper. Glad I don't have to do that here.

Although it is too late to help you, I stumbled across a GM emissions drive cycle as shown below.

U.K. Alex

Hi all
My 99 c5 just failed emissions (lambada section?) here in the UK. Was gonna try new o2 sensors but. Do you think this resetting system would help me pass it. Don't do many miles and battery disconnect most of the time.
Thanks for any advice
UK Alex

Bill Curlee

Alex

If you want to pass emissions, STOP disconnecting the battery. Each time the battery drops below a specific voltage 8 VDC for most modules, OR the battery is disconnected, The PCM DRIVE CYCLE starts over. If you are worried about the battery, keep it on a smart battery tender that wont damage a good battery.

To help us understand WHY your emissions are failing, you need to read ALL the PCM Diagnostic Trouble Codes (DTCs) and post them here. If there are a LOT of old ones, clear them all and take the car for a drive. Read the DTCs before you turn the ignition off.

READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine.
NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!
I always read my DTCs prior to turning OFF the ignition switch. If you have any messages on the DIC,, PRESS RESET until they are gone!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect.)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, "C" or "H". A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!

streamliner

Bill, so that I understand precisely, are you saying that for each of the different steps of a complete drive cycle you have to allow the engine too cool down? Or do you mean between each drive cycle? I have completed 4 drive cycles now and hope that the EVAP and CATALYST monitors will be ready after cycle number 5.

I live in Utah and don't drive it much during the winter months, I allowed my battery to go dead last winter and this winter. Won't happen again. Last year a performance car expert told me "change your gas cap" which I did and the EVAP monitor was then ready.

Thanks in advance.

streamliner

Bill,
Great info, I just learned something and it appears all 9 codes I have present are H codes in the L&R Door Control modules which I suspect are due to my battery dying.
Hoping drive cycle number 5 does the trick.

Rick

Bill Curlee

Yes,,, You do a complete drive cycle and when its done, you need to let the engine go cold iron before you do the next one.

Recommend that you clear ALL the old DTCs so that you can see if any reappear. I check my DTCs once a week or after each fill up to see if anything is having issues or had an issue. YES, a weak or low battery will often set certain DTCs. The Door modules are especially sensitive to low voltages and are a good indicator of a battery that may be weak.

A weak battery can have negative effects on your Emissions Ready Flags. If the battery is weak, the battery output voltage will dip very LOW during cold cranking and if it drops low enough the PCM and BCM can temporarily go off line due to that low voltage spike and that makes your car NOT EMISSIONS READY. Just like if you disconnect the battery prior to an emissions test. The car will be not ready. It will have to go through the required drive cycles to reset the Emissions ready flags to ready. My scanner is able to show all the module emissions flag status. I always read them prior to going to the emissions station so I don't waste my time and have to come back.

streamliner

Thanks, I appreciate your quick response and expertise. It's good to know that there is someone who can be relied upon to steer us in the right direction. I had a P0491 OBD code pop up a couple times last year and once it triggered the check engine light. It came up again during my fourth drive cycle and I reset it. When I got home from the cycle I looked on line and found out that resetting it defeated the drive cycles. I started them over again and will do my fifth one today.

Here are the DTC codes (no check engine light), I don't plan to delete them until I my EVAP and CATALYST monitors are ready.

A0-LDCM
B2282
B2284
U1064
U1096

A1-RDCM
B2283
B2285
B2287
U1064
U1096

streamliner

I noticed on the last two drive cycles when I checked the monitor status the battery voltage dropped to 13.2 volts, during the drive cycle it was 14.2 volts. Is that enough to be a problem?

RedRiderZR1

Every time I go in to do an emissions test and I have disconnected the battery, it goes through the drive cycles pretty quickly. The only one that takes quite a bit of time is the EVAP test. Easily resolved by using a TECH2. You can force that test and if everything is OK it will set it to pass.