AFM Disable Options

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,895
Reaction score
2,598
Location
(718)-
How many miles do you have to drive for the readiness monitors to be set?
The answer has nothing to do with miles at all.
Each monitor has a different set of conditions for its self-test routines.
When that self-test passes, it considers itself 'Ready'. Before the test, it's 'Not Ready'. (It can also fail its test, and throw a code.)
Knew a mechanic in the mid-2000s, had a book that told how to drive (or NOT) based on which monitor(s) were not yet ready, to ready them as soon as possible.
Only a few customers were ever allowed to read it, most other customers paid him money to keep the car for two days so he could drive it as cited in the book.
He'd always return it to them 3-4 days later.

For example:
if your EVAP system is 'Not Ready', keep the tank as close to 1/2 as possible, and try to start the car (after shutting it off) when coolant temp is ≈176F-185F.
Again, NOTHING to do with miles.
O2 sensors simply need to warm up from the cold a few times.
Catalytic converter test basically involves the rear O2s reporting .1V or .2V consistently for a given period of time in closed loop.
 
Joined
Apr 11, 2018
Posts
7,124
Reaction score
14,364
Location
St. Louis
And if I'm not mistaken, it differs with brand of vehicle. My 2002 mustang will pass all it's readiness monitors in a much shorter drive cycle then the 2012 yukon.
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,895
Reaction score
2,598
Location
(718)-
Like J91z28d1 said as well, it should be one of the earlier ones to be ready!? Weird ...
O2 sensors should also respond PREDICTABLY to EGR activation and deactivation, 0% TPS decelerations, and for GMT900 & younger, Engine Half@$$ / Cylinder Confusion activation / deactivation.
 

Charlie207

Full Access Member
Joined
Apr 13, 2021
Posts
1,654
Reaction score
3,292
Location
LFOD, New Hampshire
The answer has nothing to do with miles at all.
Each monitor has a different set of conditions for its self-test routines.
When that self-test passes, it considers itself 'Ready'. Before the test, it's 'Not Ready'. (It can also fail its test, and throw a code.)
Knew a mechanic in the mid-2000s, had a book that told how to drive (or NOT) based on which monitor(s) were not yet ready, to ready them as soon as possible.
Only a few customers were ever allowed to read it, most other customers paid him money to keep the car for two days so he could drive it as cited in the book.
He'd always return it to them 3-4 days later.

For example:
if your EVAP system is 'Not Ready', keep the tank as close to 1/2 as possible, and try to start the car (after shutting it off) when coolant temp is ≈176F-185F.
Again, NOTHING to do with miles.
O2 sensors simply need to warm up from the cold a few times.
Catalytic converter test basically involves the rear O2s reporting .1V or .2V consistently for a given period of time in closed loop.
Thanks
 

opfor2

Full Access Member
Joined
Mar 29, 2023
Posts
248
Reaction score
193
Location
Riverside County, CA
So, is California failing for detecting an aftermarket tune, or for detecting Not-Ready Monitors?
'cause it sounds like they're detecting Not-Ready Monitors, which the 'tune' is not properly handling.
That's NOT the same thing as detecting a 'tune'.
It's my understanding that they check for the OBDII not being ready and any codes.
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,895
Reaction score
2,598
Location
(718)-
It's my understanding that they check for the OBDII not being ready, and any codes.
Ok. So, unless the tune is so egregiously dumb as to roll coal, or some other blatant giveaway,
how could they possibly detect an aftermarket tune, if the checksums and CVNs are same as GM OE?
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,204
Reaction score
39,272
Location
Stockton, Ca.
Ok. So, unless the tune is so egregiously dumb as to roll coal, or some other blatant giveaway,
how could they possibly detect an aftermarket tune, if the checksums and CVNs are same as GM OE?
the "tune" check they do is primarily on the diesels, last time I had my "check" done they had no idea the blackbear tune was on it, passed with flying colors
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,895
Reaction score
2,598
Location
(718)-
the "tune" check they do is primarily on the diesels,
last time I had my "check" done they had no idea the blackbear tune was on it, passed with flying colors.
They don't do a 'tune check', because they lack the software to read or download the operational files from the pcm.
They can only check checksums and CVNs.
They had no idea the BlackBear tune was on it because the BlackBear tune had the same checksums and CVNs as GM OE.
 

Forum statistics

Threads
132,301
Posts
1,865,664
Members
96,890
Latest member
Rednim
Top