Max Lewis

I was getting codes 16 Lo-Res Fail & 36 Hi-Res Fail. I tested the ingnition module harness out like on Shoe Box's web site. I was getting power to A & D but was not getting anything from B. I have checked out the Opti harness and it's good. All fuses are good. Done a ground test that was good. So I replaced the Opti and still nothing and it's not getting any injector signal. I am woundering if it is the computer. The only thing I have not checked out is the wiring for continuity I can figure out witch harness on the computer it is.

Max Lewis

Is there anything I am missing to check out. ANYBODY

Guest47904

First let me say that I have yet to see an actually defective OBDI computer. They are indestructible. Second, I fail to understand why you wouldn't check the wiring out BEFORE you start buying things.

With little to no information given, us the readers will have to assume you have the same codes. True or false??????

The wiring from the opti to the PCM has a connector at the opti, another one about three feet away, and then at the PCM. Anywhere along the wiring or at any connector, there could be a problem. So now it's time to ohm out from the harness connector at the opti to the PCM with both ends disconnected.

As you stated above power is NOT on A & D. It's on C & D. with C being 12 volts and D being reference.

A is the low res signal on the Red/black wire going to the second pin of the black pcm connector

good luck

ACE1252

This is for a '96 Z28, but maybe it will help.

Max Lewis

The engine is cranking over but will not start. I have checked ignition fire at the coil and no spark. I have checked the fuel pressure, and it reads good. Cheked out all the fuses they are good. I checked the wiring from the opti harness to the computer harness and all the wires were good. I checked to make sure the coil was getting power and it is, also checked the primary, and secoundary resistance on the coil and that checked out good also. Ignition module was checked out at Auto Zone it was good. Checked for power at the ignition module at terminals A & D both are getting 12 volts. I am not getting any volts from terminal B. I am also not getting any signal to fire the injectors. I don't know what else to check out. When the car started having problems it just died no sputtering. The problems I am having is no spark or injector signal.

hey01

99% of the time when those 2 codes show up its the opti.

i've had 2 die on me like that and i tired to troubleshoot every trick in the book but all signs pointed back to it.

foxbat

i believe the dtc signals you have from the opti will tell the pcm to shut down spark and fuel.

i recently went through a similar intermittent start and stumble issue and it was a corroded opti (no dtc code) and a starter on it's way out.