After changing plugs and wires for misfiring and a O2 sensor I pulled the battery cable to reset the computer. How long will it take the computer to reset. I got one more chance to get it to pass emissions. It fails again it's another $40.00 and worse of all the a complete retesting.

 

Just like it set a min. You'll know you got it reset if your radio stations are gone and your needles on the instrument panel with all flip.

 

Disconnect the cable, flip the headlight switch to ON, then go take a 5 minute break.

Quote from the PCED:

"Resetting Keep Alive Random Access Memory (RAM)

Disconnect the battery ground cable for a minimum of 5 minutes. Resetting Keep Alive RAM will clear learned values the PCM has stored for adaptive systems such as idle and fuel trim.

After Keep Alive RAM has been reset, the vehicle may exhibit certain driveability concerns. It will be necessary to drive the vehicle to allow the PCM to relearn values for optimum driveability and performance."



It takes some time (more than a minute) to drain the storage capacitor that supplies the NVRAM.

One minute is adequate for the SRS system, but the PCM can require quite a bit more time.

 

Good info anyway, I did not know there are storage caps to drain. I left it off for about 10 mins with nothing on to drain system. It is a 98 Scab 4.6 auto I am not sure which computer it has.

Thanks

 

It should be drained just fine.

You will need to complete at least two complete driving cycles in order for all the onboard monitors to run.

If you take it in for a retest too soon, you will get a P1000 code which will tell the inspectors that the battery was very recently disconnected, perhaps to reset a CEL....

Steve

 

Thanks again.