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If I want to take my batteries and have them tested I know that I have to remove them. But If I take both the batteries out wont the computer loose its memory and the memory in the transmission and such will ALL reset to inital settings? I have a 99 7.3 and my question is this......
**)If I take one battery out and have it tested, put it back and then do the same to #2, will they memory stay intact since complete power was never lost?
If I want to take my batteries and have them tested I know that I have to remove them. But If I take both the batteries out wont the computer loose its memory and the memory in the transmission and such will ALL reset to inital settings? I have a 99 7.3 and my question is this......
**)If I take one battery out and have it tested, put it back and then do the same to #2, will they memory stay intact since complete power was never lost?
The computer will not loose its memory if you disconnect the batteries.
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The computer will not loose its memory if you disconnect the batteries.
I'm afraid that your statement isn't completly correct. It is true that the basic strategy program will not be lost.......but if battery power is lost for more than five minutes, all of the information that the PCM has learned about the type of driving the truck has gone through will be. The PCM will have to re-learn optimum shift points, fine adjustments to timing etc. after the battery power is reconnected.
The answer to the poster's question is no......the learned PCM adjustments will not be lost if one battery at a time is taken out for testing. As long as 12 volts is supplied, the learned adjustments will be ok.
I've heard of people doing this intentionally....kinda a "Poor Man's Flash" to reset the ECM with ALL ECM after market programs re-set to stock or chips taken out first. But, after both batteries were removed, they said to klick the positive and negative terminals together to insure a "Flash" or "Re-set" to take place. Would you guys recommend this procedure?
What I've heard is to disconnect the battery terminals, then turn the headlights on to drain any residual power in the pcm. Reconnect the batteries, and your pcm has been reset. You will have lost any codes that might have been stored, but that only makes the truck run better.
But, after both batteries were removed, they said to klick the positive and negative terminals together to insure a "Flash" or "Re-set" to take place. Would you guys recommend this procedure?
I don't recommend this; because there will be someone....some place that will take that to mean it's ok to short positive and negative together without disconnecting the second battery. That can be very expensive.
The "keep alive five" circuit was designed to keep the PCM powered during a battery change out on single battery vehicles.
It's function is not effected by shorting the positive and negative leads.
It's design is kind of lost on Diesels though, because of the two battery system . I guess you'd have to be pretty quick to change out both batteries within that five minute time.
I don't recommend this; because there will be someone....some place that will take that to mean it's ok to short positive and negative together without disconnecting the second battery. That can be very expensive.
Can you say: " Boiling battery and melted cables?" LOL.
If I want to take my batteries and have them tested I know that I have to remove them. But If I take both the batteries out wont the computer loose its memory and the memory in the transmission and such will ALL reset to inital settings? I have a 99 7.3 and my question is this......
The 4R100 in your 99 does not learn anything. If you remove both batteries all that you will lose is your radio station settings.