reg_255

Hello All,

I'm reposting my question in the Tech/Performance section for help from people that might not read the General discussion area.

I have a H16 (not current) code that will not stay cleared out of memory.

When I can get the code to clear, it just returns.

I've removed the battery cables, tried through the DIC.
All to no avail.

Separated the ECM connector from the Optispark pigtail. DC voltage at pin A back to the ECM is 4.7v.
Reconnected the pigtail and check at the pigtail end, voltage is 4.7v dc.

The displayed code is H16, no other codes, no Service Engine Soon.

Things that have been replaced in the last 3 months.
Spark plugs
Plug wires
Vented Optispark (Petris)
Water pump
Analog Coolant temp sensor.
Digital Coolant temp sensor.
O2 sensors
PCV valve
Drive belt
Flushed Radiator / new hoses
Had ECM tested (no trouble found)

Engine starts, idles and seem to generally run OK.

Any help with getting rid of this cockroach of a code is greatly appreciated.

Regards,
Roy

bogus

Even resetting via the DIC?

Silly question... when you turn on the key to start the car, does the SES light come on? I wonder if the bulb is blown and the code is legit.

antfarmer2

Clean both ends of the opti pigtail and connections and try again

reg_255

The SES works, I can set a code and it will illuminates.

You mentioned clearing the code through the CCM. Did you happen to find the procedure?

reg_255

The pigtail is new, I replaced it when the code would not clear out.
I do have electrical connector cleaner, will clean the harness end of the connection.

bogus

I will get them tonight.

kimmer

Any news on the outcome?

reg_255

Hey Kimmer,

Thanks for asking.

I kind of temporarily gave up on the H16 code.
I was just getting aggravated with no progress.

The car starts and runs/idles in the driveway, so I decided to working on some of the other issues to feel like something was being fixed.

I've replaced;

Fuel Injector O rings
Fuel Pressure Regulator
Intake Manifold Gasket
Stripped and painted the Valve Covers
New Valve cover Gaskets
A/C Clutch
Replaced the A/C controller
I have the Steering Wheel column out to fix the Loose tilt function.

Looking forward to fixing reinstalling the column to see if the A/C functions properly.

Regards,
Roy

Christi@n

Did you ground the obd plug with paper clip, and deleted code with proper procedure using dash button?? And it come back?



16 code from chilton manual

Direct ingnition system (DIS), fault line circuit or Distributor ignition system (or low resolution pulse) or Missing 2X reference circuit or Optispark ingnition timing system (Low resolution pulse) or System voltage out of range

kimmer

My code 16 won't wont go away either even though it'e all fixed. I just won't let it bother me.

reg_255

That's the line of thought I'm taking, for right now.
It will be in the back of my mine bugging me, but if it runs fine I will get over it.

Want to get some of the other issues addressed so I can drive it.
Due to 3 back 1 neck surgery and broken heal bone (not all at the same time), I can only work for short periods of time on the car.

I bought it last October, still have only driven up and down my block after a repair.

Does yours run fine with the H16 code?

Regards,
Roy

kimmer

She runs great, the code is from the opti I just replaced, I don't understand why so many of us are having that problem.

reg_255

What brand of Opti did you use?

WVZR-1

I would think the code 16 can't be avoided with likely the replacement of any Opti without the **OE sensor. I believe that if you do the code 16 diagnostics and the car runs well you have to disregard the code 16 and "drive on".


** A optical sensor with the same specs and also likely the wheel.

kimmer

I put a Petris in, seems to be running very good and I like that it's vented.

cardo0

U need to use the TRIP RESET button to get to module 4.0 (ECM) then press to get to 4.7. Now press and hold the ENG/MET button until "_" is displayed. This is for ECM module 4 codes. CCM module 1 code are cleared differently. Heres a good link: http://tech.corvettecentral.com/2011...trouble-codes/

Good luck.

WVZR-1

I don't believe anyone actually has a problem clearing the Code 16 initially BUT if the system isn't seeing what it wants the 16 goes directly to H (History) and even when cleared the system is going to see it again and stuff it back into the history. If you clear it and it stays "gone" you're good to go, if it reverts back to "HISTORY" then you need to confirm the run/functionality of the system and "ignore".

reg_255

U need to use the TRIP RESET button to get to module 4.0 (ECM) then press to get to 4.7. Now press and hold the ENG/MET button until "_" is displayed. This is for ECM module 4 codes. CCM module 1 code are cleared differently. Heres a good link: http://tech.corvettecentral.com/2011...trouble-codes/

Been there done that, got the Tee Shirt.





I can clear the code, It just comes right back as a H16 code.

Ominous Z06

I have the same exact problem in my '93 LT1. I also have a Petris Opti. It's frustrating, because I changed the opti as the car would not idle or stay running, and died on accelerator. I thought it was my MSD unit dying. The car still will not run with the Petris, and I can't tell if there is a problem with the Petris unit as the H16 code will never reset. It is the only DTC code I get.

cardo0

The DTC 16 means the PCM is not getting the 4 low res pulses for every 360 hi res pulses inside the Opti. Myself i would use an oscilloscope on the low res black & red wire from the Opti. U can "back pin" the connector for this. Sometimes u can just stuff a unbent paper clip in with the wire and connect your scope to this paper clip. If the scope has 2 channels u can look at the high resolution pulse and compare as the hi res signal has 90 times more pulses per revolution. If u dont see this then u have a problem inside the Opti.

For setting up the scope, pulses will only be 5v so use the 10v or 100v scale setting. And @ 1000 rpm u will get only 67 lo res pulses/sec so use 0.01sec/div for freq.

But i have read that the car will not start w/o the low res pulse. U have to prove this for your self. But u then have the issue down to just a few possibilities.

No lo res pulse = grounded red/black wire or bad Opti.

Good lo res pulse = open red/black wire between Opti connector and ECM or bad ECM.

Hope this helps.