HELP! Clearing codes through a 'Drive Cycle'?

Originally Posted by atikovi
Coincidentally I almost bought one of these wagons this week from Super Shuttle, a 2017 with 320,000 miles. It went for what the 200,000 mile ones sold for, so [censored] no. The emissions monitors must me completed before it can pass but depending on the model year, one or two may still be incomplete and you can pass. You can check with a cheap OBDII scan tool every now and then to see if they have been completed so you don't go to the inspection for nothing.
Well it is reassuring to know that some of them have lived that long... seeing as mine has only 51k on it now, if it's possible for it to go for that long I'll be pretty happy.
 
Originally Posted by drh214
Originally Posted by wag123
Assuming that there isn't something wrong with the vehicle, when you do a drive cycle properly the readiness codes can be made ready on most vehicles in less than 10 miles, and it takes roughly 30 minutes from start to finish. I have done it at least 100 times. If you just drive the vehicle around it can take weeks. The procedure needs to be followed EXACTLY. It needs to be done first thing in the morning when the vehicle has been sitting all night and the engine is cold. If it is hot outside in the summer (like it gets where I live) and the engine doesn't get cold enough overnight, the computer will never be ready. Fortunately, I had an air conditioned garage that i could leave the vehicles in overnight. Something else that I found out from experience is that if the battery is weak or if there is something wrong with the charging system, the computer will NEVER be ready. This is something that they don't tell you. When I put the vehicle in the garage overnight I always put a battery charger on it to top it off.
This is super helpful. Thank you. I am actually thinking that maybe the battery is going, because last weekend I was vacuuming it out with the key in turned back and it killed the battery. I am wondering if I charge or change the battery this would take care of the cold start RPM problems too. I drove it this afternoon, kinda very split second slow start to turn over, then drove for a bit, parked shortly then drove again, no problem on the start... then we went to see Star Wars, so it was parked for over 2 hours, cold start and it took several seconds to start and the RPM needle bounced a bit. Going to troubleshoot the battery tomorrow and then if that doesn't fix it, start looking into the Throttle Body, OCV, airflow issues etc...
If you disconnect the battery, you will be in the not ready state again for the readiness monitors for the emissions. If you can charge it without disconnecting it, that should be fine.
 
Originally Posted by drh214
Originally Posted by wag123
Assuming that there isn't something wrong with the vehicle, when you do a drive cycle properly the readiness codes can be made ready on most vehicles in less than 10 miles, and it takes roughly 30 minutes from start to finish. I have done it at least 100 times. If you just drive the vehicle around it can take weeks. The procedure needs to be followed EXACTLY. It needs to be done first thing in the morning when the vehicle has been sitting all night and the engine is cold. If it is hot outside in the summer (like it gets where I live) and the engine doesn't get cold enough overnight, the computer will never be ready. Fortunately, I had an air conditioned garage that i could leave the vehicles in overnight. Something else that I found out from experience is that if the battery is weak or if there is something wrong with the charging system, the computer will NEVER be ready. This is something that they don't tell you. When I put the vehicle in the garage overnight I always put a battery charger on it to top it off.
This is super helpful. Thank you. I am actually thinking that maybe the battery is going, because last weekend I was vacuuming it out with the key in turned back and it killed the battery. I am wondering if I charge or change the battery this would take care of the cold start RPM problems too. I drove it this afternoon, kinda very split second slow start to turn over, then drove for a bit, parked shortly then drove again, no problem on the start... then we went to see Star Wars, so it was parked for over 2 hours, cold start and it took several seconds to start and the RPM needle bounced a bit. Going to troubleshoot the battery tomorrow and then if that doesn't fix it, start looking into the Throttle Body, OCV, airflow issues etc...
First, connect a OBDII code reader and see if it is storing any codes. If there are any codes stored/pending the computer will never become ready and the problem will need to be resolved. The CEL will not necessarily be ON when the computer is storing codes. Second, if it has the original battery, replace it. It is at least 3 years old and it is likely weak and on it's way out anyway. This is also the likely cause of your starting problem first thing in the morning. If the battery is weak the computer will never become ready. Also, a weak/bad battery can cause the computer to throw-up and store voltage related fault codes (most of the sensors rely on proper and stable reference voltages). Third, after you replace the battery you will need to perform an idle relearn procedure. Fourth, after you do the idle relearn procedure you will need to do a drive cycle procedure. Make sure the the engine is COLD before you do this. The very first part of the drive cycle procedure where you start a cold engine and let it idle (without touching the throttle) with all of the lights and accessories ON for three minutes is CRITICAL to your success. Also, make sure that you have the correct amount of gas in the tank before you start. Use the the OBSII code reader to check the readiness status and you should leave it connected while you are doing the drive cycle so you can monitor your progress. You can have one not-ready (or incomplete) and it will pass the emission test. The third and fourth procedures will have to be done again ANY time you disconnect the battery, or if the battery goes dead (like it did on you).
 
Last edited:
The saga continues. I got in it this morning to take it to have the battery tested, before starting it up I popped the hood to take another look at the coolant levels. Coolant levels looked fine. Got in, started it up, it turned over fine, RPMs didn't 'bounce', but the CEL was back on. Took it to have the battery tested and the codes read. The code that it is throwing is still an engine coolant code.... eek mad Battery tested fine (as far as the tech could tell... the battery on these vans is tucked back in an inconvenient spot). The van is back at the shop... I guess I'll find out more on Monday. AGH!!!!!
 
Originally Posted by drh214
The saga continues. I got in it this morning to take it to have the battery tested, before starting it up I popped the hood to take another look at the coolant levels. Coolant levels looked fine. Got in, started it up, it turned over fine, RPMs didn't 'bounce', but the CEL was back on. Took it to have the battery tested and the codes read. The code that it is throwing is still an engine coolant code.... eek mad Battery tested fine (as far as the tech could tell... the battery on these vans is tucked back in an inconvenient spot). The van is back at the shop... I guess I'll find out more on Monday. AGH!!!!!
So, there was a fault code stored/pending. Like I said before, the computer will never become ready if there is a fault code stored/pending. You need to go ahead and pony-up for an inexpensive OBDII Scanner Code Reader https://www.amazon.com/Autel-MaxiScan-MS300-Diagnostic-Vehicles/dp/B001LHVOVK/ (now under $18). I still strongly recommend that you go ahead and replace the battery. I don't care what the tech "thinks". Good luck.
 
Last edited:
Thanks, yep it's in the shop now. I bought the ODBII scanner this weekend at Harbor Freight, and I will be replacing the battery too. Good news is it's still running. Thanks again for all your help.
 
Had the garage you sent the vehicle to for inspection actually checked the coolant level they would have seen it was low. Had they pressure tested the cooling system they would have found the leak. Drivin can clear codes but not always - either get Carly in your phone or a cheap scanner off eBay/amazon I suggest you never use that place again
 
Last edited:
I posted a thread about drive cycles and hurrying up the clearing process a few months ago. My work schedule has been hectic this year. Last September, I swapped injectors in my 09 Suburban. I disconnected the battery to do it. A few days later, driving home from the train station after work, I noticed my inspection sticker was expired. I cannot leave it parked all day like that. I will get ticketed. Completely forgetting that I had the battery disconnected a few days earlier, I drop the truck off to be inspected. Al, the mechanic, calls me and says what did you do? It hit me like a ton of bricks. I posted on here and someone posted the correct procedure for GM vehicles. (Thank you again). Took a couple evenings but the computer finally went into ready mode. I have an Innova code reader that displays a red, yellow or green light showing state of readiness. Prior to knowing the procedure, I drove it for a week and nothing. The hardest part was finding a road where I could coast down to 20 from 55.
 
Originally Posted by atikovi
Coincidentally I almost bought one of these wagons this week from Super Shuttle, a 2017 with 320,000 miles. It went for what the 200,000 mile ones sold for, so [censored] no. The emissions monitors must me completed before it can pass but depending on the model year, one or two may still be incomplete and you can pass. You can check with a cheap OBDII scan tool every now and then to see if they have been completed so you don't go to the inspection for nothing.
Do you know that for sure? I can't find anything on the Maryland MVA's website indicating how many incompletes that I can have.
 
I'm more familiar with Virginia. https://www.deq.virginia.gov/Progra...icleOwners/UnderstandingOBDMonitors.aspx Monitors and the OBDII Inspection During the OBDII inspection process, the emissions inspection analyzer asks the vehicle's OBDII system to provide the status of all of its OBDII monitors. If there are too many monitors that indicate "Not Ready," the analyzer will reject the vehicle from testing. For most 1996 to 2000 model year vehicles, up to 2 monitors are allowed to be in a "Not Ready" condition. For most 2001 and newer model year vehicles, only one monitor is allowed to be in a "Not Ready" condition. If more than the allowed number of monitors are "not ready," the vehicle will be rejected from testing. In addition, if the vehicle failed the initial emissions inspection for a "catalyst related" diagnostic trouble code, then the catalyst monitor must be "ready" in order to complete the re-test, regardless of the normal allowance of not-ready monitors.
 
drh214 said:
Sorry I wasn't clear. The check engine light is off and has been off since the second trip to the shop when I brought it home. It did sit in my driveway for more than 24 hours after that. So it was a rough start this morning and that's when the rough/strange idle happened too. It's not had any rough starts since and starts right up, no problem now. I don't have much to base this assumption off, but I've found in my Subaru, that the first start up after codes have cleared can be rough... Not sure if that could be the same here... Anyway, it's not currently showing any indicator lights nor is the check-engine light on.
Click to expand...
Try Google search, the process for my 2005 Buick Century was very specific, and if not followed to the letter would fail. A typical drive cycle usually involves a cold start, defined as IAT temp being a differential to Ambient temp. Next, get out of open-loop ASAP,(open loop fuel trim may be your issue), the procedure involved loading the electrical system so the Alternator would put out max amps to get the O2 sensors ready. turn on the rear defroster, headlights, and AC. Then drive on roads at 30-40mph and highways at 60mph. the tough part was NOT braking, and trying to coast to a halt.
 
drh214 said:
Originally Posted by wag123
Assuming that there isn't something wrong with the vehicle, when you do a drive cycle properly the readiness codes can be made ready on most vehicles in less than 10 miles, and it takes roughly 30 minutes from start to finish. I have done it at least 100 times. If you just drive the vehicle around it can take weeks. The procedure needs to be followed EXACTLY. It needs to be done first thing in the morning when the vehicle has been sitting all night and the engine is cold. If it is hot outside in the summer (like it gets where I live) and the engine doesn't get cold enough overnight, the computer will never be ready. Fortunately, I had an air conditioned garage that i could leave the vehicles in overnight. Something else that I found out from experience is that if the battery is weak or if there is something wrong with the charging system, the computer will NEVER be ready. This is something that they don't tell you. When I put the vehicle in the garage overnight I always put a battery charger on it to top it off.
This is super helpful. Thank you. I am actually thinking that maybe the battery is going, because last weekend I was vacuuming it out with the key in turned back and it killed the battery. I am wondering if I charge or change the battery this would take care of the cold start RPM problems too. I drove it this afternoon, kinda very split second slow start to turn over, then drove for a bit, parked shortly then drove again, no problem on the start... then we went to see Star Wars, so it was parked for over 2 hours, cold start and it took several seconds to start and the RPM needle bounced a bit. Going to troubleshoot the battery tomorrow and then if that doesn't fix it, start looking into the Throttle Body, OCV, airflow issues etc...
Click to expand...
Read my post on what is a true Cold Start, PLEASE do not throw parts at your problem, it never ends well. Try to beg, borrow a code reader that shows fuel trim, various sensor readings. DRH214, hit the nail on the head, low battery readings will screw the computer. Additionally, you can reset the computer to the factory by removing the battery, connect leads together to drain capacitors, etc. Then start with a new or known fully charged battery and let the old girl warm up and drive about 50 miles mixed driving.
 
atikovi said:
I'm more familiar with Virginia. https://www.deq.virginia.gov/Progra...icleOwners/UnderstandingOBDMonitors.aspx Monitors and the OBDII Inspection During the OBDII inspection process, the emissions inspection analyzer asks the vehicle's OBDII system to provide the status of all of its OBDII monitors. If there are too many monitors that indicate "Not Ready," the analyzer will reject the vehicle from testing. For most 1996 to 2000 model year vehicles, up to 2 monitors are allowed to be in a "Not Ready" condition. For most 2001 and newer model year vehicles, only one monitor is allowed to be in a "Not Ready" condition. If more than the allowed number of monitors are "not ready," the vehicle will be rejected from testing. In addition, if the vehicle failed the initial emissions inspection for a "catalyst related" diagnostic trouble code, then the catalyst monitor must be "ready" in order to complete the re-test, regardless of the normal allowance of not-ready monitors.
Click to expand...
Only one monitor for 2005
 
Codes trigger the light, drive cycles set the readiness monitors and usually it's when the oxygen sensor and coolant sensor set their values. Is a very large broad stroke generalization but it's basically true.
 
You must log in or register to reply here.

Similar threads

zrxkawboy
ANCO TRICO
Replies
1
Views
264
JayhawkRoy
LazyDog
Voyager Van Cover Time
Replies
2
Views
266
LazyDog
R
Earl Scheib
2
Replies
24
Views
826
walterjay
dogememe
Chevy Express Pricing and 6-Speed Trans
2
Replies
26
Views
1K
dogememe
daves87rs
Very hard stop shuts car down
Replies
19
Views
490
daves87rs
Top