94_PatriotRed_Z

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.

Injuneer

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.

marshall93z

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.

94_PatriotRed_Z

Thank you guys, I will try pulling the fuse and see which codes come back first.

94_PatriotRed_Z

I checked all the connections yesterday, and they are seem to be good.

Does anyone else have any help before I order an opti?

Injuneer

Did the codes come back right after you pulled the fuse?

94_PatriotRed_Z

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?

94_PatriotRed_Z

Does anyone know if my problem might be fixed? or do I still need to replace the opti?

Stl94LT1

Opti problems can be intermitten before it finally dies.

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!!

coreander

any help???

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.

94Z28LS1toLT1

did you ever find out about your code 42? I am having the same exact problem as you were.

94Z28LS1toLT1

did u ever fix your problem with code 42

Injuneer

"coreander" has not returned to this site since May 2009.