Electronic Spark Module ... future MY 90 Achilles Heel?

[GOLDCYLON]

While browsing parts for my cars on EBay I noticed a part there in the mix I never noticed before. I have been driving my 1991 ZR-1 for 12 years now however just over a year ago I bought a 1990 ZR-1. A few of you know that the MY 90 had a few differences technically that did not follow into the different model years as the electronics and the engines for that matter improved. While almost everybody knows about the ECM and the DIS that are failure points along the entire model run I propose that I have stumbled upon a MY 90 potential problem area that I was completely unaware of. While I am fairly knowledgeable about ZR-1s I will be the first to tell you I know several members in the community that have probably forgotten more than I will ever know lol.

The ESC is also called the electronic knock module. It provides an modular interface between the knock sensor and the ECM. On earlier C4s it was located near the evaporator housing and in the 90 ZR-1 it is located on the evaporator suitcase below the radiator high fill point. In 1991 ZR-1s and on later cars ESC was incorporated into the memcal in the ECM. When the ECM detects knock (pre-ignition), it will retard the timing to save the engine from damage. This will sometimes result in a loss of power and pinging and overall poor running conditions. Just like the MY1990 air bag frame rail sensors and the Air Bag DERM module the ESC I believe is a MY 90 ZR-1 LT5 ONLY specific part. I have no idea on availability of this item however I suggest as our cars continue to age that this might be an area of concern. I suggest if you can find one you add it to your parts store if you own a 1990 ZR-1.

I have personally not heard of a failure of the ESC However Usually a Service Engine Code will be thrown if it fails. If it fails "silently" your ECM will not be able to detect any pre-ignition due to bad gas, improper timing, electronic misses etc. and you may damage your engine if not replaced. There is one of these currently on EBay for sale that I advise may be a good item to stock away. Here is that EBay auction number 192441750427. (Not my auction and not affiliated in any way shape or form) just passing along the information.

The GM part number and interchange number is 16080211, D1931A

Just my thoughts your mileage may vary. GC

[-=Jeff=-]

Yep.. Another thought is run 1991 ECM Code (repin the ECM) and figure out the key module then run the 1991 ESC..

[GOLDCYLON]

Yep.. Another thought is run 1991 ECM Code (repin the ECM) and figure out the key module then run the 1991 ESC..

-=JEFF=- lol while you are an electrical guru and this may be the solution I am glad I am not the guy trying to figure that out. Yikes

[-=Jeff=-]

Easy.. actually I have it all marked out and I was going to try it (but with 1992 code an CCM)

I think the swap would be straight forward, another thought is to have someone look into the BIN code and find the 1990 stuff and 1991 stuff and integrate the 1991 ESC stuff to the 1990 BIN File..

Now I need to look at it again

[-=Jeff=-]

Just looked..

Get a 1991 power switch ( unless you are bypassing it) I am sure I can figure out a way to use the 1990 switch for the 1991 design

run a new wire to the knock sensor and get a 1991 knock sensor.

Add the ESC board to the PROM.. Run 1991 code..
I think that is it..

[XfireZ51]

Just looked..

Get a 1991 power switch ( unless you are bypassing it) I am sure I can figure out a way to use the 1990 switch for the 1991 design

run a new wire to the knock sensor and get a 1991 knock sensor.

Add the ESC board to the PROM.. Run 1991 code..
I think that is it..

Jeff,

Are u suggesting to use the 91 Mask for a 90 ZR? Is there a difference in the 90-91 sensor? I would think the frequency would be the same for any of the LT5s?


On a different vein, the ECM runs a forced knock test. Some info from RBob over at ThirdGen.

This is from ThirdGen.Org. RBob is a moderator there and a tuning guru among other talents.

“Code 43 is set by one of two different ECM tests. The first test is run-away knock. If within a period of 3.9 seconds more then ~245 knock counts are detected code 43 will be set. This can be caused by an open wire or a non-existent knock filter.
The other test is that the ECM will advance the spark timing in order to force knock (detonation). The ECM will attempt this twice, the second time with more advance then the first. If both forced knock tests fail code 43 will be set.
The forced knock test takes place under PE conditions. Once knock is detected PE and HighWay SA is now in effect and the forced knock test is done.
“Hook up a scan tool and check the knock counts. If the counts are constantly incrementing then you have run-away knock. You then have either an open wire or the filter is bad.
If after some spirited driving there is no knock and code 43 pops up, then either knock did not occur or the knock sensor/filter is not reporting it. If no knock is reported then test the system by holding the rpms > 1200-1400 RPM and rap on the engine block. This should be picked up as knock.
If so then you'll need to figure out why the ECM can't force the knock. Check the timing and the EGR system. Have you checked to see if the chip is stock? Maybe running 93 octane can do it?”

May need to check filter (ESC).

[-=Jeff=-]

Yes.. biggest challenge will be to get the power key to function.. but I think it is doable

[XfireZ51]

Yes.. biggest challenge will be to get the power key to function.. but I think it is doable

The addresses aren’t even close.

[-=Jeff=-]

The addresses aren’t even close.

I know.. it will require 3 new wires on the 1990 harness..

- New Knock Sensor
- Power Key reference
- Power Key Light

I need to find the reference values for full power and valet. Also the Light on the 1990 DIC would get rewired. I can use an Arduino if needed to handle the logic change of the power key, if function is to be retained,

then just run Stock 1991 code in the 1990 ECM, I think the 1990 CCM should be able to chat with the 1991 ECM code..

[Ccmano]

Not sure if anyone has noticed this but the module in question 16080211 is at least physically identical to the knock module used in the 84-86 Corvette 16022621. If we can verify that it is electronically identical we may have something. There may other versions for the 87 and up L98 as well. It’s a long shot but who knows. Here are photos of both.
H
:cheers:

16080211 for the 90 LT5

http://a63.tinypic.com/1zx5l5s.jpg

16022621 for the 84-86 L98

http://a68.tinypic.com/33vi2qw.jpg

[XfireZ51]

Doubtful Hans given that the L83 and L98 were iron blocks and ours of course is aluminum/open deck. Not to mention the valvetrain noise. Frequency filtering would be different.

[-=Jeff=-]

I am sure they are different in some way.

[GOLDCYLON]

Yep the form factor is identical however there is an internal reason why the Part numbers are different as the 90 ZR-1 has its own part number. GC

[Dynomite]

While almost everybody knows about the ECM and the DIS that are failure points along the entire model run I propose that I have stumbled upon a MY 90 potential problem area that I was completely unaware of. While I am fairly knowledgeable about ZR-1s I will be the first to tell you I know several members in the community that have probably forgotten more than I will ever know lol.



The ESC is also called the electronic knock module. It provides an modular interface between the knock sensor and the ECM.



Just my thoughts your mileage may vary. GC


I might add one other item that can fail ;)

I would say Fuel Pressure Regulator (FPR)......and yes.....your milesge will vary when you start sucking raw fuel into plenum when the FPR fails :D


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[XfireZ51]

Mechanical issues have had “work arounds” and adaptations but when it comes to electronics we are in a totally different realm.
Let me just add that this is the type of initiative the Registry needs to be more pro-active in to fulfill our mission statement of “Keeping the Legend Alive”.

[GOLDCYLON]

Mechanical issues have had “work arounds” and adaptations but when it comes to electronics we are in a totally different realm.
Let me just add that this is the type of initiative the Registry needs to be more pro-active in to fulfill our mission statement of “Keeping the Legend Alive”.

Concur. I know Jerry is working on a solution for the DIS on his own dime and we would be in a real hurt lock real quick if folks like Phil had not put together a solution for the fuel pressure regulator. I had a good discussion with Dom last night with electronics we are all on borrowed time. Even having a replacement used part on hand is not a long term solution. It is concerning. GC

[GOLDCYLON]

It also looks like somebody took my advise and bought that module on EBay. :cheers:

I hope it went to a club member as I did not put this info out on Corvette Forum. GC

[Scrrem]

Yes it did and thanks! I have been meaning to pick one up for a while and you reminded me. I have never heard of one of these going bad but you nene know.
Rich

[Ccmano]

Doing a little research over on Corvette Forum in the C4-Tech-Performance (not ZR-1) section. It appears that 16080211 is the Knock module for all 90’s not just the Z.

Does anyone have a parts cross reference to confirm this?

Check out the last post in this ancient thread.

https://www.corvetteforum.com/forums/c4-tech-performance/155665-paging-65zo1-others-about-esc-module-part.html

This exact reference comes up in a number of threads with regard to “false knock “ in L98’s.
“The part numbers for different years are:
'85-'86 p/n 16022621 - New p/n 16126761
'87-'89 p/n 16052401 - New p/n 16038331
'90 p/n 16080211”

H
:cheers:

[Dynomite]

I will check a 1990 (L98) tomorrow for knock module. Pete should also have one on that 1990 Z he is parting
out.


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[GOLDCYLON]

Doing a little research over on Corvette Forum in the C4-Tech-Performance (not ZR-1) section. It appears that 16080211 is the Knock module for all 90’s not just the Z.

Does anyone have a parts cross reference to confirm this?

Check out the last post in this ancient thread.

https://www.corvetteforum.com/forums/c4-tech-performance/155665-paging-65zo1-others-about-esc-module-part.html

This exact reference comes up in a number of threads with regard to “false knock “ in L98’s.
“The part numbers for different years are:
'85-'86 p/n 16022621 - New p/n 16126761
'87-'89 p/n 16052401 - New p/n 16038331
'90 p/n 16080211”

H
:cheers:

Interesting but still a one year part I will be anxious to see what is on Cliff's 90 L-98

[Ccmano]

Wholesale GM Parts Online shows this less than conclusive but nevertheless interesting note.

http://a63.tinypic.com/312folj.jpg

[Ccmano]

Interesting but still a one year part I will be anxious to see what is on Cliff's 90 L-98

True, but still better than a ZR-1 exclusive part. That is if this pans out.
H
:cheers:

[-=Jeff=-]

I don’t think 1990 L98 has them. 1990 F-Body did not, quite sure the newer design ESC was on the L98 and followed to the ZR-1 in 1991

[GOLDCYLON]

Cliff will need to take a peak

[XfireZ51]

1990 L98 Knock Sensor is different OEM part# than 1990 LT5 which would suggest that ESC modules are not the same as well.

[GOLDCYLON]

1990 L98 Knock Sensor is different OEM part# than 1990 LT5 which would suggest that ESC modules are not the same as well.

My thoughts as well. Cliff can put this one to rest once he looks at his 90 L-98

[WVZR-1]

I'm quite sure Cliff won't find one. The L98 ECM wiring is in your '90 FSM. '90 L98 KS is pinned to ECM.

8A-20-5 for (L98) - 8A-22-3 for (LT5)

There's good news though maybe - that style ESC/KSM (call it what you like) was used for many years and they varied widely dependent very much on the engine. V6 - V8

I'm quite sure there's applications thru likely '95

Function? Well ............................. I guess YTBD

[Dynomite]

I cannot find it on 1990 (L98)??


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[GOLDCYLON]

Ok confirmed this is a one-year only ZR-1 part with possibility of a replacement to be yet determined. And according to Han's online search NLA. GC :cheers:

[Ccmano]

I cannot find it on 1990 (L98)??


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We tried. So unless some can determine the electronic differences and some how update the earlier ones, repair the ones we have or build new ones we are SOL.
H



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[GOLDCYLON]

We tried. So unless some can determine the electronic differences and some how update the earlier ones, repair the ones we have or build new ones we are SOL.
H



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It would take somebody of -=JEFF=-'s caliber to tear both an early C4's module apart and a 90 ZR-1 module apart to see what the difference is as the form factor is identical. Maybe it's as simple as unpinning a wire or changing a capacitor. This would be a great project for the club to invest in. As Dom states we are all on borrowed time electronically. GC

[-=Jeff=-]

It would be better easier to convert to 1991 BIN and knock setup

[GOLDCYLON]

It would be better easier to convert to 1991 BIN and knock setup

:eek: I would have to take your word on that -=JEFF=-

[-=Jeff=-]

Did some looking.. you could change the 1990 Calibration to the 1991 Calibration by doing the following:
- Change to the 1991 Knock sensor and add the wire going to the ECM
- Add the 2 wires for the Power Light and Power Input to the ECM
- Simple Relay circuit wired between the new Power wires and the Key and light.
- Add the knock PCB to the MEMCAL
- use a 1991 Definition and BIN file and it should work


** I am assuming the CCM will not complain between 1990-1991, I think the CCM-ECM streams are the same. 1991 adds features on the CCM side, like DAB, Oil level and turn signal chime..

EDIT.. I have not tried this yet

[jrd1990zr1]

FYI

Someone on E-bay has a bunch of the 16080211 Knock sensors for $59.00 each. Claims they are new not used. I just bought one for a spare.

John

[GOLDCYLON]

FYI

Someone on E-bay has a bunch of the 16080211 Knock sensors for $59.00 each. Claims they are new not used. I just bought one for a spare.

John

Good find. I have a spare already hopefully other MY90 owners will consider just in case. GC

[XfireZ51]

Altho =Jeff= and I discussed a way of utilizing the 91-95 proms w on-board KS for the 90s.

[TX '90 ZR1]

I snagged one for my spares also.
Thanks for the heads-up guys.
:cheers:

[WVZR-1]

FYI

Someone on E-bay has a bunch of the 16080211 Knock sensors for $59.00 each. Claims they are new not used. I just bought one for a spare.

John

I snagged one for my spares also.
Thanks for the heads-up guys.
:cheers:

I'd be interested in some better snapshots of what you guys bought and also maybe some 'date code' info. Snapshots on the eBay offering lack much detail.

[32valvZ]

White Racing has a used one on ebay for $290.? and these others are $60.? Something seems fishy... I know WR isnt the best place to buy from, but thats a pretty big gap for whats supposed to be the same part. I am unable to fully make out the stamped numbers on the part... but from what I can see, theyre not the same as whats on the first page of this thread.

[-=Jeff=-]

If someone can confirm the stamped numbers once received, that would be great

[jrd1990zr1]

I could make out the part number on the photograph in the ebay ad and it matches the one on my car. Could not make out the date code after the part number.

Mine has been shipped so I'll update when it arrives.

[-=Jeff=-]

I could make out the part number on the photograph in the ebay ad and it matches the one on my car. Could not make out the date code after the part number.

Mine has been shipped so I'll update when it arrives.

That would be fantastic, THANKS

[32valvZ]

Cool deal.... if the numbers are the same someone is going to make a few bucks real quick! :fahne:

[TX '90 ZR1]

I have one coming also. For $59.00 I figured it was worth a shot.
When it arrives I will post numbers also.
If anyone has the capability to check it I would be glad to send it to you to verify it is a correct part.
We will see when it arrives.
:cheers:

[jrd1990zr1]

If someone can confirm the stamped numbers once received, that would be great

Jeff,

Got it today. It has the part number 16080211 melted into it just like the one on my 1990. It has a date code of 0019. It appears to be the real deal from what I can see. Guess the only way to tell for sure would be to hook it up in my car and see if it works.

Do you or GC know of any way to test it without installing it on my car. I am a bit hesitant.

Thanks, John

[-=Jeff=-]

Reach out to Marc Haibeck to see if he knows a way to test it

[jrd1990zr1]

Reach out to Marc Haibeck to see if he knows a way to test it

I just sent Marc an e-mail. Have to see what he says.

Thanks, John

[mgbrv8]

My worst case scenario would probably be a stand alone system by Haltech or maybe something better when ever the time comes. Also I could have a true sequential fuel injection instead of bank style injection

https://www.haltech.com/product-category/universal-ecu-kits/

Dave

[32valvZ]

I asked the seller to post a close up shot of the stamped number and he did so... in case anyone was interested. Its just like John said is on his.

[tpepmeie]

My worst case scenario would probably be a stand alone system by Haltech or maybe something better when ever the time comes. Also I could have a true sequential fuel injection instead of bank style injection



https://www.haltech.com/product-category/universal-ecu-kits/



Dave



Why do you think you don’t have sequential injection now?




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[-=Jeff=-]

I have reason to believe this seller is Ken Anderson, he used to rebuild LT5 ECMs

Reason is the receipt I got is K&B Special Products.. same company name that did our ECMs

[jrd1990zr1]

I have reason to believe this seller is Ken Anderson, he used to rebuild LT5 ECMs

Reason is the receipt I got is K&B Special Products.. same company name that did our ECMs

Jeff,

FYI, My invoice for the module is also from K&B special products. I did get a response from Marc about testing the module, but I don't have the equipment to test it. I am hoping another Registry buyer can verify these modules are "wired" properly.

John

[-=Jeff=-]

Knowing more now and if these are from Ken, I have more confidence that they are genuine. Was it in a Delco box or loose?

[jrd1990zr1]

Knowing more now and if these are from Ken, I have more confidence that they are genuine. Was it in a Delco box or loose?

It was loose, in bubble wrap, securely packaged in a small priority mail shipping box.

I wonder if these were originally purchased in bulk, no individual boxes? I did send the seller a note thru E-bay asking him how he came to have so many (15). No response yet.

[Dynomite]

It was loose, in bubble wrap, securely packaged in a small priority mail shipping box.

I wonder if these were originally purchased in bulk, no individual boxes? I did send the seller a note thru E-bay asking him how he came to have so many (15). No response yet.


Only 4 left...….they will be gone today :p

[Ccmano]

Sold out...
H
:cheers:

[TX '90 ZR1]

Sold out...
H
:cheers:

Maybe he should pay us a commission ! ? ;)
This is the same seller that had a couple of Euro-spec instrument clusters. Our members sucked them up too.
Wonder what else he has??
:cheers:

[32valvZ]

Son of a beeoch!!! I missed getting one.... Anyone buy 2 and want to sell one?

[garyhugo]

Received mine today. Just as described. Didn't order two.
Now can we find Wheel speed sensors for the 90 my.

[jrd1990zr1]

Received mine today. Just as described. Didn't order two.
Now can we find Wheel speed sensors for the 90 my.

Gary, Are you talking about the LTPWS bands in the tires?

John

[GOLDCYLON]

Jeff,

Got it today. It has the part number 16080211 melted into it just like the one on my 1990. It has a date code of 0019. It appears to be the real deal from what I can see. Guess the only way to tell for sure would be to hook it up in my car and see if it works.

Do you or GC know of any way to test it without installing it on my car. I am a bit hesitant.

Thanks, John

John I do not.

[GOLDCYLON]

Gary, Are you talking about the LTPWS bands in the tires?

John

He is

[Dynomite]

Received mine today. Just as described. Didn't order two.


I did and got one today :cheers:

[GOLDCYLON]

I did and got one today :cheers:

Cool looks like a lot of members are set! ;)

Just in case that is ......

[32valvZ]

Because of one of our awesome brothers, I now have one on the way...

[WVZR-1]

Now can we find Wheel speed sensors for the 90 my.


Gary, Are you talking about the LTPWS bands in the tires?

John

He is


I doubt that!!!!

I'd think Gary knows difference WSS and LTPWS

[GOLDCYLON]

I doubt that!!!!

I'd think Gary knows difference WSS and LTPWS

Lol I read it too quick WV I believe you are right !!!!!

[jrd1990zr1]

Guys,

Just got a notice the seller posted another ad on e-bay for the modules. Price is now $79.00. Has more than 10 available.

[spork2367]

Guys,

Just got a notice the seller posted another ad on e-bay for the modules. Price is now $79.00. Has more than 10 available.

It's the same guy with the euro spec. instrument clusters that he keeps listing individually. He probably has a pallet of these as well.

[TX '90 ZR1]

Received mine today. Looks just like the one on my car, right down to the "GM" logo. With the other batch being sold, looks like there should be enough in the system for a while.
Any body going to be the test mule and check one of these out? =D>
:cheers:

[Hib Halverson]

My worst case scenario would probably be a stand alone system by Haltech or maybe something better when ever the time comes. Also I could have a true sequential fuel injection instead of bank style injection

https://www.haltech.com/product-category/universal-ecu-kits/

Dave

LT5 is not a bank-fire system. It's SEFI. In fact, it was the first SEFI engine from GM.

The idea of going to a 91-95 controller then changing harnesses and calibration seems like the best way to proceed.

[mgbrv8]

Thanks Hib:cheers:


Dave




LT5 is not a bank-fire system. It's SEFI. In fact, it was the first SEFI engine from GM.

The idea of going to a 91-95 controller then changing harnesses and calibration seems like the best way to proceed.