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2005 DeVille
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10 Posts
Discussion Starter #1
Have an 05 DeVille, replaced both crank position sensors and all wiring between sensors and ecm. Still showing codes,also can't clear them. Car runs like it should,but can't pass emissions. How can I reprogram the ecm manually without a scan tool?
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,998 Posts
Have an 05 DeVille, replaced both crank position sensors and all wiring between sensors and ecm. Still showing codes,also can't clear them. Car runs like it should,but can't pass emissions. How can I reprogram the ecm manually without a scan tool?
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you can't "reprogram" a PCM even WITH the TECH2 scan tool -

not sure WHY you can't clear the codes - unless they are still CURRENT -

you're ONLY shot would be to disconnect BOTH battery cables and touch them together for 5 seconds -
 

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Super Moderator
2003 Deville Base
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5,267 Posts
most auto parts store scan tools will only read codes, but you can't program features. I trust Basscatt's word on the PCM. Disconnecting the cables & touching them together is somewhat like a re-boot on a computer. Be sure you disconnect the negative first, then the positive. Reconnect positive first, then the negative.
 

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2005 DeVille
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Discussion Starter #4 (Edited by Moderator)
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you can't "reprogram" a PCM even WITH the TECH2 scan tool -

not sure WHY you can't clear the codes - unless they are still CURRENT -

you're ONLY shot would be to disconnect BOTH battery cables and touch them together for 5 seconds -
TOUCH THEM TOGETHER? FOR 5 SECONDS? HOLY SHIT! REALLY?!

ARE YOU SURE? SOUNNDS A LITTLE NUTS!
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,998 Posts
ARE YOU SURE? SOUNNDS A LITTLE NUTS!
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re-read EXACTLY what I wrote -

disconnect BOTH battery cables and touch them together for 5 seconds

this discharges the small amount of electricity that is stored in the various capacitors
and clears the VOLATILE memory of the modules -

NO - it isn't nuts -

NO - it won't hurt anything - IF you do it correctly -
 

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2005 Cadillac Deville
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86 Posts
^^^^^^^^^ What he said. If you disconnect the battery as instructed, there will be NO power in the system to cause any harm. ^^^^^^^^^^
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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The only way to re-flash the PCM (Powertrain Control Module) to your Northstar car's original specifications is at a GM dealership. About $100. Why do you think the PCM has lost something? Once faults are repaired and the OBD-II system checks out the repairs it will automatically send any current codes to history and they will self-clear from memory after XX successful start-run-drive events.

Touching the disconnected battery cable end terminals together clears many modules and it will take a while for the car to re-learn some stuff and you may have to reset personalization settings and radio settings.

........... and which codes (and their definitions) are still showing during a code pull sequence in the DIC message strip ?
 

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2005 DeVille
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10 Posts
Discussion Starter #8
So I disconnected both cables and held them together. Didn't clear anything,not even radio presets. Tried it with a computer I got and the original, didn't clear anything. With the original computer, which is in the car now I can clear the code. If I leave the car run the light stays off,as soon as I shut it off and start it again it returns. Any ideas?
 

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2005 DeVille
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10 Posts
Discussion Starter #9
P0385 crankshaft position sensor B circuit malfunction. The car runs and drives great,gets 17,18 mpg city. Takes an extra second or two to fire when starting, always has.
 
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