Service Engine Soon light on AGAIN....... - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1987-1991 Parley with regards to your 1987 to 1991 Bonneville, Olds 88 or Buick Le Sabre Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 02-01-2006, 02:39 AM   #1
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default Service Engine Soon light on AGAIN.......

i walked out to the bonne today and was greeted with my sirius satellite radio saying UPDATED on the screen so i had that working now then i look down at the dash and i see the SERVICE ENGINE SOON light on and im like "here we go again" to myself, i pulled the code and it was code 43 Electronic spark control circiut or Knock sensor problem

this is the second time this code has randomly shown up in the last few months, once with the magnavox ignition and now with the delco. so im thinking its the knock sensor more than the spark control unit. would the knock sensor cause a random minute of heavy misfiring at idle and as soon as you tap the gas it goes away and may or may not come back at idle. cuz my car does this. i swear this thing has the worst case of pms ive ever seen in my life.

*edit* also i was getting a code for system lean a few weeks ago. it went away after a reset and never came back but would that have anything to do with this?
DarkShadow is offline   Reply With Quote
Old 02-02-2006, 12:10 AM   #2
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default

oh come on, nobody knows anything about this? :(
DarkShadow is offline   Reply With Quote
Old 02-02-2006, 10:02 AM   #3
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Wish I had something for you... These two items aren't really my specialty.. will post link in GH for you.
BillBoost37 is offline   Reply With Quote
Old 02-02-2006, 10:35 AM   #4
BANNED
 
Join Date: Aug 2002
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
banned3800 is on a distinguished road
Default

Disconnect the battery for a minute and blank all of the codes... Reconnect the battery... Ground the diagnostic pin in the ALDL, turn the ignition on( engine off ) and pull the codes again... You should only get a code 12.... If you get no codes pull the jumper, start the car and drive it and if the SES come back on check the codes again( engine off )... After you do that report back..

__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
banned3800 is offline   Reply With Quote
Old 02-03-2006, 11:25 PM   #5
Senior Member
Posts like a 4 Banger
 
Join Date: Mar 2005
Location: Appleton, WI
Posts: 124
Thanks: 0
Thanked 0 Times in 0 Posts
2seater is on a distinguished road
Default

Maybe on the knock sensor, but it would cause the ECM to pull timing rather than a misfire. You can sometimes get the engine to stumble by tapping on the engine with a wrench or hammer. The knock sensor will see it as knock and may pull timing. It depends how sensitive it is. If it is installed too tightly, it may be overly sensitive. You don't have a knock at idle that goes away at higher rpm maybe? You could also have a problem with the harness that runs across the front of the engine. It connects to the cam and crank sensor and also carries the "EST" or electronic spark timing signal, to the ignition module from the ECM. The car starts using programming in the ICM under the coils only, and then when the rpm comes up the ECM sends a signal to overide the module timing and runs under ECM control for the timing. If the EST signal is lost, the engine reverts to the base timing in the ICM, sometimes called limp home mode, that has fixed timing of about 10 degrees advance. The engine will run, but performance will suffer. Maybe an intemittant connection or insulation rubbed through?
2seater is offline   Reply With Quote
Old 02-04-2006, 02:54 AM   #6
Senior Member
Posts like a Corvette
Thread Starter
 
Join Date: Jun 2005
Location: Berkeley, IL
Posts: 1,596
Thanks: 0
Thanked 0 Times in 0 Posts
DarkShadow is on a distinguished road
Default

Quote:
Originally Posted by 2seater
Maybe on the knock sensor, but it would cause the ECM to pull timing rather than a misfire. You can sometimes get the engine to stumble by tapping on the engine with a wrench or hammer. The knock sensor will see it as knock and may pull timing. It depends how sensitive it is. If it is installed too tightly, it may be overly sensitive. You don't have a knock at idle that goes away at higher rpm maybe? You could also have a problem with the harness that runs across the front of the engine. It connects to the cam and crank sensor and also carries the "EST" or electronic spark timing signal, to the ignition module from the ECM. The car starts using programming in the ICM under the coils only, and then when the rpm comes up the ECM sends a signal to overide the module timing and runs under ECM control for the timing. If the EST signal is lost, the engine reverts to the base timing in the ICM, sometimes called limp home mode, that has fixed timing of about 10 degrees advance. The engine will run, but performance will suffer. Maybe an intemittant connection or insulation rubbed through?
you know the wires do look kinda crappy on that harness, theres an exposed one in one part right after the plug in the icm
hmmmmmmm.
DarkShadow is offline   Reply With Quote
Old 02-04-2006, 08:15 PM   #7
Senior Member
Certified GM nut
 
Join Date: Feb 2004
Location: CT
Posts: 2,099
Thanks: 0
Thanked 1 Time in 1 Post
SSEBONNE4EVA is on a distinguished road
Default codes

Bad connections are allways suspect on intermitten codes.
I would reset it like Jr said and also remove the ICM connector and tighten up on the sockets. (takes patience and a tiny screwdriver). Then put it on and off a couple times, apply dielectric grease and see how it goes.
SSEBONNE4EVA is offline   Reply With Quote
Old 02-06-2006, 02:38 PM   #8
Senior Member
Certified GM nut
 
Join Date: Feb 2004
Location: CT
Posts: 2,099
Thanks: 0
Thanked 1 Time in 1 Post
SSEBONNE4EVA is on a distinguished road
Default misfire

One other thought:
A bad plug or wire could cause a random misfire that engages the knock sensor.
The ECU then retards the timing until the knock goes away.
SSEBONNE4EVA is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
got service vehicle soon light, trac off and abs light on at same time blaze420711 Pontiac 6 10-19-2014 11:54 PM
service engine soon light on. Jrios 2000-2005 8 04-13-2004 05:33 PM
Service Engine soon Light SSEimatt93 General GM Chat 8 06-09-2003 02:16 PM
Service Engine Soon Light Cheap00Bonneville 1992-1999 4 01-04-2003 10:53 PM
SERVICE ENGINE SOON LIGHT PROBLEM 94SSEgold 1992-1999 4 01-01-2003 08:47 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:35 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.