Hmm, car was running fine last weekend, but when I went to start it up on a pretty cold Monday morning it would not turn over and start. It would attempt to, but would not catch so i know it isn't the battery or starter although I played with those too just to be sure. Now today is fairly warm, 62 deg, and I was finally able to get my car to start, although it sounds pretty rough. Checked the Scanmaster and got a DTC 16- OptiSpark low resolution pulse not found. Since I was under the impression that this was a stored code as the car will not start with a DTC 16 I went to clear the code by removing the negative battery terminal. But after that I got the same results...Car will start with some effort, idles rough, and I still get the same code. Is the opti about to die...again, or is there something else I can do here? Don't want to start driving it and then have it leave me stranded somewhere. Any advice would be greatly appreciated!! TIA...

 

Well, it does sound very opti-ish. You might check the harness connections on both ends before deciding that you need to replace it.

 

Here's a simple test you could do.

The wires from the opti have a connector about 2 feet from it. Disconnect it at that connector and probe pin A which is the red/black wire on the side going to the PCM. Don't probe the connector side that goes to the opti. With the other lead on ground, turn the key on but don't crank the engine.

(1) If the voltage is less than .5 volts DC, either the low res. wire is open or grounded. Or the PCM connection is faulty or the PCM is bad.

(2) If the voltage is greater than 6 VDC, the low res signal wire is shorted to battery voltage.

If the voltage is between 4 and 6VDC, turn key off. Reconnect the connector and disconnect it at the opti this time. Now probe that connector just as before on the red/black wire with the power on.

See (1) or (2) above as before. If the voltage is 4 to 6 volts now, you either have a faulty opti connector or the opti itself is faulty

 

Please have patience with me on this as I'm not too familiar with electrical components, but here's what I got... Grounded the black probe and tested PCM side pin A with the red probe. Recieved a 5V reading, so I think I can cross that out. I was going to do the connector on the opti, but that things was way down there. I'm going to have to take some pieces off to get to it if I'm looking at the right connector. Anyway, when you say the connector, are you talking about the wire portion, or the connector on the optispark? I ask because if the connector on the optispark is the culprit then wouldn't the whole opti need to be replaced? Thanks!!

 

The opti optical sensor is dying and will soon leave you stranded if not replaced. Is your water pump leaking on it?

 

Nope, I couldn't find any evidence that the waterpump had been leaking.

 

I have very similiar symptons to this. After having to take the radiator off to get to the accessory bracket (had a power steering pump bolt strip out) I'm sure I spilt some water in the direction of the opti. After putting it all back together it started up and ran terrible for a few minutes, I turned it off, wouldnt start back. Hooked the laptop up to it, got the error code for low res. pulse error (DTC 16 I think). It hasn't started since. I did the test earlier in this post and also found ~5V, I tried the test on shoebox's page involving the connector at the ICM and a multimeter on AC, looking for 1-4 volts or so, I could never get anything over 2 volts (my multimeter has a max hold featuer). I went ahead and took the opti off, pulled it apart and it looked pretty good actually, bearing was fine and the optical side was clean, a little oil has leaked in there somehow but that was about it. Obviously there's more to it than it just looking clean thogh. Anyways, the distributor side looked pretty nasty, so i cleaned that up with some light sand paper to just get off the corrosion. Put it all back together, put it on, ran a wire off the coil to a brand new spark plug i had laying around, grounded it, hooked the timing light to that wire and turned it over and its not firing at ALL.

It did the exact same thing one other time and after it sat a week or two it started up, after some revving and holding it above ~2500RPMs, it eventually started running right, until now. It's been two days atleats since I had the radiator off and it hasnt started since. Sometimes it will randomly fire once or twice and almost start then not do anything again for a while. I'm thinking this is the opti, but am open to any other suggestions before I go spend the money on this thing....THanks.

Carson

 

Remind me to check fuses next time before I take the opti off...

Replaced the fuse, car started right up but is running like doo-doo. Timing light is still hooked up to the coil wire and is flashing pretty randomly, and its obvious some cylinders arent firing consistently...Now, whats wrong May be it just needs a good driving, I'm sure it being cranked without firing up the last few days a lot isn't the greatest for the plugs but if it doesn't clear up soon I'm gonna have to start buying some new ignition parts...

Carson

 

I am having a problem just like this one. I had some problems starting my car when it was cold in the morning, but if I reved to 2000 rpm for a minute it would run fine.

Recently I was out of the country for 3 months and the temperatures have dropped a lot, and it is still cold now that I have gotten back.

When I try to start the car i get code 16, doesn't start, no spark. Reset the codes with my freescan software, try to start again and the code 16 comes up again.

Am I right in assuming that the low resolution error is referring too camshaft position detection?

Is this normal thing to go wrong in the opti? I thought it usually failed in the High voltage section.

 

From my recent reading, it looks to be pretty common. Without the low res. pulse no fuel will be injected by the pcm. I sprayed a little starting fluid in the intake and it started right up for a few seconds, idled, cut off...You might give it a try just to make sure its still firing, but more than likely its the opti, so plan on replacing it

Carson