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Oil change light on 3800 series 2 sc by TbirdMarc
Started on: 02-19-2014 02:04 PM
Replies: 9 (383 views)
Last post by: phonedawgz on 02-21-2014 12:51 PM
TbirdMarc
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Report this Post02-19-2014 02:04 PM Click Here to See the Profile for TbirdMarcClick Here to visit TbirdMarc's HomePageSend a Private Message to TbirdMarcEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm in the process of building up the harness on my 3800sc series 2 swap into my 88 formula. All the diagrams I see say to delete the wiring to the sensor in the oil pan. I would like to have the change oil feature retained in the swap. Would there be any issues in doing this? I would probably hook a yellow LED somewhere in the OP pod. I know I would need to retain this in programming the PCM, but I do like the idea of keeping the sensor. Anyone else done this?
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tebailey
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Report this Post02-19-2014 03:56 PM Click Here to See the Profile for tebaileySend a Private Message to tebaileyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Why? I have it on 2 of my cars and it never works right.
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phonedawgz
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Report this Post02-19-2014 05:07 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Oil level <> oil change light.

From what I am seeing on a 2000 GTP the Oil Change light is on C2 pin 36 Clear and the Oil Level Low light is on C2 pin 6. The ECM grounds the pin in both cases so the other end of the light needs to be wired to 12V switched. Not sure if a different year PCM will wire differently for these functions.

You could use the shift light wiring for one of these two functions.
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TbirdMarc
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Report this Post02-20-2014 04:04 PM Click Here to See the Profile for TbirdMarcClick Here to visit TbirdMarc's HomePageSend a Private Message to TbirdMarcEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tebailey:

Why? I have it on 2 of my cars and it never works right.


I have it on several of my cars and it works great, thus the question.
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TbirdMarc
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Report this Post02-20-2014 04:07 PM Click Here to See the Profile for TbirdMarcClick Here to visit TbirdMarc's HomePageSend a Private Message to TbirdMarcEdit/Delete MessageReply w/QuoteDirect Link to This Post

TbirdMarc

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quote
Originally posted by phonedawgz:

Oil level <> oil change light.

From what I am seeing on a 2000 GTP the Oil Change light is on C2 pin 36 Clear and the Oil Level Low light is on C2 pin 6. The ECM grounds the pin in both cases so the other end of the light needs to be wired to 12V switched. Not sure if a different year PCM will wire differently for these functions.

You could use the shift light wiring for one of these two functions.


I figured the sensor was for oil change because it's a glass tube inside the oil pan so I reckon it must shine a beam and read the reflection of the dirty oil. I could be way off though.
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phonedawgz
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Report this Post02-20-2014 04:36 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
The oil level sensor is a normally closed switch that opens when the oil level is low. The PCM only looks at it at start up since once the engine is running you don't want the light flashing on and off in corners ect.

The PCM counts revolutions of the engine and considers engine load to figure out when to activate the oil change needed light.



[This message has been edited by phonedawgz (edited 02-20-2014).]

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Darth Fiero
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Report this Post02-20-2014 05:09 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by TbirdMarc:


I figured the sensor was for oil change because it's a glass tube inside the oil pan so I reckon it must shine a beam and read the reflection of the dirty oil. I could be way off though.


The sensor/switch in the oil pan is just for oil level, it doesn't tell the PCM how dirty the oil is. Furthermore, the "glass tube" sensor you refer to is an early version of the low oil level sensor that was discontinued after 1996 or 97 model year in favor of a simple switch design. Neither of these worked flawlessly, just FYI.

The oil change indicator function works based on calculations the PCM performs using information like engine run time, engine running conditions, accumulated mileage since last reset, etc. My 2003 Buick LeSabre has a 3800 with an oil life display function on the dash and it takes about 8000 miles for it to indicate an oil change is required (going from 100% oil life left down to 0% oil life left). So I don't trust it much.

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

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TbirdMarc
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Report this Post02-21-2014 09:48 AM Click Here to See the Profile for TbirdMarcClick Here to visit TbirdMarc's HomePageSend a Private Message to TbirdMarcEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Darth Fiero:


The sensor/switch in the oil pan is just for oil level, it doesn't tell the PCM how dirty the oil is. Furthermore, the "glass tube" sensor you refer to is an early version of the low oil level sensor that was discontinued after 1996 or 97 model year in favor of a simple switch design. Neither of these worked flawlessly, just FYI.

The oil change indicator function works based on calculations the PCM performs using information like engine run time, engine running conditions, accumulated mileage since last reset, etc. My 2003 Buick LeSabre has a 3800 with an oil life display function on the dash and it takes about 8000 miles for it to indicate an oil change is required (going from 100% oil life left down to 0% oil life left). So I don't trust it much.

-ryan



Thanks for the info Ryan. Given that info, I will probably ditch the whole oil level/change option and save myself the trouble. Didn't realize the oil change algorithm was so unreliable, works great on my Lincoln and Ford!
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TbirdMarc
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Report this Post02-21-2014 12:02 PM Click Here to See the Profile for TbirdMarcClick Here to visit TbirdMarc's HomePageSend a Private Message to TbirdMarcEdit/Delete MessageReply w/QuoteDirect Link to This Post

TbirdMarc

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Member since Oct 2011
 
quote
Originally posted by phonedawgz:

The oil level sensor is a normally closed switch that opens when the oil level is low. The PCM only looks at it at start up since once the engine is running you don't want the light flashing on and off in corners ect.

The PCM counts revolutions of the engine and considers engine load to figure out when to activate the oil change needed light.







Phonedawgz do you have a link to DL the wiring diagrams, very helpful in understanding.
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phonedawgz
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Report this Post02-21-2014 12:51 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
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