What is the best way to test the ECM to see if it is working correctly.
What is the best way to test the ECM to see if it is working correctly?
- Thread starter 99black
- Start date
Start the Jeep.
What is happening that makes you think the PCM is not working correctly?
Start the Jeep. If you get no codes everything is working. If you get codes either something is wrong with the engine or tranny or something is wrong with the PCM.
You can attach a obdII scanner, check for codes, the check the monitors if you have any incomplete monitors run a drive cycle until the monitors clear. This will test all the engine control and emission systems to verify they are working correctly.
Working on my sons 1999, manual trans 4.0 L, TJ that won't stay running & battery not keeping full charge. My son has replaced many parts already... new fuel pump, crank sensor, new battery, alternator & starter, ignition switch etc. I'm thinking PCM. I've replaced the PCM on my 2006 TJ 4.0L automatic trans with a new WranglerFix, high performance tune, because I had the hard 1st-second shift which it fixed. Now my question... can I try and plug my old PCM, 2006 auto, into the 1999 manual TJ to see if that would fix the running problem without damaging anything before he buys a new one from WrangleFix? Does the PCM have to be close to the year & trans of the TJ just to test a engine running issue? No codes are shone.
I believe auto and manual trans are completely different pcm's.
They are also programmed for specific trans as well.
So, you can plug it in but don't expect anything to operate properly.
Just my guess...
Will be visiting my son this 4th of July weekend and will be working on his TJ.
How about switching the computer with one from a 1997 manual transmission? Just want to rule out the PCM is not the cause of the Jeep not starting. Since there is no check engine warning light being shone I think that maybe that is the reason for the new fuel pump not running. My son is very worried about me changing the computer thinking it will cause damage to it or the Jeep and leave him with 2 non running Jeeps. I don't want to be "holding the bag" if it does. He refuses to "throw in the towel", admit defeat and have it towed to a professional mechanic even if I offered to pay...
How about switching the computer with one from a 1997 manual transmission? Just want to rule out the PCM is not the cause of the Jeep not starting. Since there is no check engine warning light being shone I think that maybe that is the reason for the new fuel pump not running. My son is very worried about me changing the computer thinking it will cause damage to it or the Jeep and leave him with 2 non running Jeeps. I don't want to be "holding the bag" if it does. He refuses to "throw in the towel", admit defeat and have it towed to a professional mechanic even if I offered to pay...
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What years are the two jeeps? What color are the keys of the two jeeps? What transmission is in the two jeeps?
What engines are in the two jeeps?
If the keys are gray they have a skim unit and won’t swap.
If the transmissions are both manual or both autos they will swap.
Gotta be both 4 bangers or six.
Years…..meh.
What engines are in the two jeeps?
If the keys are gray they have a skim unit and won’t swap.
If the transmissions are both manual or both autos they will swap.
Gotta be both 4 bangers or six.
Years…..meh.
Here's a ideer, send it to Mark and have him test it ! THAT WAS EASY .....
Gave my son the phone # & address of WranglerFix to do that about a month ago... he, for some reason, won't do it.
you know the old saying "you can lead a horse to water but you can't make him drink "
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