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Old 03-16-2012, 07:44 PM
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Is there a way to reset the PCM .

I just had all my injectors replaced because one was clogged. Now I want to reset the PCM so I can relearn everything. How do I do that?
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Old 03-16-2012, 08:08 PM
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Re: Is there a way to reset the PCM .

Disconnect battery overnight or a starscan/scan tool and reset all adaptives.

Who replaced the injectors?
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Old 03-16-2012, 08:14 PM
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My mechanic did. He's awesome !
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Old 03-16-2012, 08:24 PM
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Re: Is there a way to reset the PCM .

He should have reset all the adaptives also.

As long as he replaced the injectors with the same size you should be fine reguardless of a reset.
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Old 03-16-2012, 11:58 PM
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I have yet to personally see a failed injector cause driveability concerns.... let alone justification for replacing all 8. Not that they dont fail, just not super common.

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Old 03-17-2012, 12:50 AM
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It's more and more common due to ethanol, and only one failed, but he got my warranty company to pay to replace them all. I really trust this guy, and he's one of my friends. We hooked it up to the diagnostic computer and that said that one of the injectors was running really really lean. So we pulled it out and moved it to another cylinder. And the same thing happened. So it was defiantly the injector.
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Old 03-17-2012, 05:14 AM
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Re: Is there a way to reset the PCM .

This is the way I have always done it.
Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
Reconnect the Battery Cable
Turn Ignition Switch to the “On” position but DO NOT start the engine
Turn Headlight “On”
Turn Headlights “Off”
Turn Ignition Key “Off”
When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory. When you get the engine up to operating temperature, the PCM will start to collect data for the “Adaptive Memory”. The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.
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Old 03-18-2012, 07:43 PM
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Re: Is there a way to reset the PCM .

Quote:
Originally Posted by 2005JGC View Post
I have yet to personally see a failed injector cause driveability concerns.... let alone justification for replacing all 8. Not that they dont fail, just not super common....
It happens. I had to do a mechanic's diagnosis because StarScan can't tell that.

My #8 and #5 fuel injectors failed between 50K and 60K miles. Oversll LTFT #1 and #2 were very high. Seems like they were failing closed. The condition continued to degrade.

Lackluster acceleration, reduced mpg's, DTC's (pending & active), O2 sensor issues. [My 4.0L I-6's had better performance.]

I finally got the dealer to replace all 8 fuel injectors and the symptoms have disappeared.
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Old 03-21-2012, 08:33 AM
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Re: Is there a way to reset the PCM .

Quote:
Originally Posted by Gojeep View Post
This is the way I have always done it.
Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
Reconnect the Battery Cable
Turn Ignition Switch to the “On” position but DO NOT start the engine
Turn Headlight “On”
Turn Headlights “Off”
Turn Ignition Key “Off”
When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory. When you get the engine up to operating temperature, the PCM will start to collect data for the “Adaptive Memory”. The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.
Never should you remove the positive battery terminal first; always remove the negative, or you are asking for a potentially dangerous situation. Car batteries store and deliver an enormous amount of energy very quickly, easily a few hundred amps, more than an arc welder.
I know a guy who did this and the battery exploded, causing very serious acid burns. H2SO4 fumes are highly explosive and any slight spark from the pos terminal can set it off.
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Old 03-22-2012, 02:13 AM
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Re: Is there a way to reset the PCM .

Came from a Jeep manual
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Old 03-22-2012, 07:51 AM
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Re: Is there a way to reset the PCM .

You did not read the manual correctly then. THere is no manual that would tell anyone to disconnect the positive first. Only do this after first removing the negative. Same goes in reverse, connect the positive first, then the negative. IF you remove the postive first, and it touches anything, it will ground, and the very high current is not just an explosive danger, the noise generated from the ground spark can damage IC's in any number of vehicle electronics. ALl you have to do is disconnect the neg for several minutes and the PCM resets. I've done this may times on the WK.
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Old 03-24-2012, 06:01 AM
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Re: Is there a way to reset the PCM .

On my XJ that has never worked as memory is kept longer than a few minutes. Tried it and idle was still even normal after restart showing it still had memory. If memory is fully discharged, took quite a while for the ECU to get idle regular again.
I must buy a lottery ticket to as never had a problem in 30 years taking off the positive first. Damn those old timers for teaching me incorrectly. Also read the you should always connect the positive jumper cable first and take it off first too and connect the negative to the chassis or other ground apart from the battery terminal to prevent a spark igniting any gasses from the discharged battery. Does that still apply?
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