LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Car Stalls: DTC 16, 36, 42

Old Mar 10, 2009 | 07:59 PM
  #1  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
Car Stalls: DTC 16, 36, 42

I searched and know 16 (Distributor ignition system (low resolution pulse) and 36 (Distributor ignition system (faulty high resolution pulse or extra low resolution pulse detected) are both common Opti codes, but code 42 (Ignition Control (IC) circuit (shorted or grounded circuit) is what Im not sure about.

Car will rev fine with no load, drive fine then out of no where just cut off, and a min later with start right back up and drive fine sometimes or cut off sometimes. Car has fuel pressure after it cuts off. I have changed out both the ICM and Coil with no luck.

So my main question is code 42 making the opti codes(16 & 36) set or is it the other way around?

Any help is GREATLY appreciated, Thank You in advance.
Old Mar 10, 2009 | 11:12 PM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
The Opti codes indicate the PCM is not picking up the high and low resolution pulse signals from the Opti. It must be an intermittent problem, because when the PCM can't find the low res pulse (DTC 16) it shuts down the fuel system - pump and injectors. The problem can be due to a faulty optical module in the Opti, or corrosion or pin damage to the two harness connectors between the PCM and the Opti.

Clear the codes (pull the "PCM BAT" fuse for 30 seconds) and see how fast they come back. If it dies, and sets DTC 16 at the same time, it will confirm the problem with the optical module or the wiring to the Opti.

DTC 42 can be caused by a large number of problems, and a faulty Opti is one of them. To diagnose DTC 42, best thing you can do is find a copy of the diagnostic "tree" diagram from the factory shop manual.
Old Mar 10, 2009 | 11:24 PM
  #3  
marshall93z's Avatar
Registered User
 
Joined: Feb 2003
Posts: 2,639
From: Mooresville, NC
All my problems with these codes and getting stranded ended up being a bad connection at the ICM. That was a hard one to find.
Old Mar 11, 2009 | 06:08 AM
  #4  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
Thank you guys, I will try pulling the fuse and see which codes come back first.
Old Mar 27, 2009 | 12:16 PM
  #5  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
I checked all the connections yesterday, and they are seem to be good.

Does anyone else have any help before I order an opti?
Old Mar 27, 2009 | 07:15 PM
  #6  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Did the codes come back right after you pulled the fuse?
Old Apr 7, 2009 | 05:50 PM
  #7  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
Originally Posted by Injuneer
Did the codes come back right after you pulled the fuse?
I just got around to pulling the fuse and resetting the codes, drove the car all around town today and had no problems. It never stalled and the codes did not come back. Does this mean my problem might be fixed? Or is there still something I need to replace so this problem does not come back?
Old Apr 10, 2009 | 08:49 PM
  #8  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
Does anyone know if my problem might be fixed? or do I still need to replace the opti?
Old Apr 10, 2009 | 10:35 PM
  #9  
Stl94LT1's Avatar
Registered User
 
Joined: Apr 2006
Posts: 1,083
From: O'Fallon, MO
Opti problems can be intermitten before it finally dies.
Old Apr 12, 2009 | 10:00 PM
  #10  
coreander's Avatar
Registered User
 
Joined: Apr 2009
Posts: 6
ok dont really mean to thread jack....but im having the exact same problem with the exception that i dont have code 16. just 36 and 42. i think my problem lies within the white wire going to the ICM. i have continuity with 0 resistance. but while cranking the engine....i only read 0.6 Vac. so if i am correct....this means that my harness to my opti or the opti is bad? oh yea this is a jegs brand opti that was put on 2 weeks ago. ran fine for a couple days....then one day...just goes to **** on me!!
Old Apr 14, 2009 | 03:32 PM
  #11  
coreander's Avatar
Registered User
 
Joined: Apr 2009
Posts: 6
any help???
Old Apr 20, 2009 | 06:44 PM
  #12  
94_PatriotRed_Z's Avatar
Thread Starter
Registered User
 
Joined: Jul 2005
Posts: 697
From: Greenville, NC/ Daytona Beach, FL
Well I went and picked up my car today from my friends house and drove it the 100 miles home with no problems. I hope whatever was the problem is fixed.

I have replaced both the coil and ICM, and then pulled the fuses to reset the codes.
Old Dec 13, 2014 | 10:24 PM
  #13  
94Z28LS1toLT1's Avatar
Registered User
 
Joined: Aug 2009
Posts: 769
From: las vegas
Re: Car Stalls: DTC 16, 36, 42

Originally Posted by 94_PatriotRed_Z
Well I went and picked up my car today from my friends house and drove it the 100 miles home with no problems. I hope whatever was the problem is fixed.

I have replaced both the coil and ICM, and then pulled the fuses to reset the codes.
did you ever find out about your code 42? I am having the same exact problem as you were.
Old Dec 13, 2014 | 10:27 PM
  #14  
94Z28LS1toLT1's Avatar
Registered User
 
Joined: Aug 2009
Posts: 769
From: las vegas
Re: Car Stalls: DTC 16, 36, 42

Originally Posted by coreander
ok dont really mean to thread jack....but im having the exact same problem with the exception that i dont have code 16. just 36 and 42. i think my problem lies within the white wire going to the ICM. i have continuity with 0 resistance. but while cranking the engine....i only read 0.6 Vac. so if i am correct....this means that my harness to my opti or the opti is bad? oh yea this is a jegs brand opti that was put on 2 weeks ago. ran fine for a couple days....then one day...just goes to **** on me!!
did u ever fix your problem with code 42
Old Dec 14, 2014 | 08:53 AM
  #15  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Re: Car Stalls: DTC 16, 36, 42

Originally Posted by 94Z28LS1toLT1
did u ever fix your problem with code 42
"coreander" has not returned to this site since May 2009.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jazsun
Cars For Sale
0
Dec 29, 2014 12:14 PM
1996LT1Z28
Middle Atlantic
3
Dec 4, 2014 09:37 PM
1996LT1Z28
Show and Shine / Paint and Body Care
2
Dec 4, 2014 09:20 PM
USAirman93
General 1967-2002 F-Body Tech
4
Nov 24, 2014 03:37 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 01:17 PM.