Electronic Spark Module ... future MY 90 Achilles Heel? - ZR-1 Net Registry Forums

GOLDCYLON · 02-23-2018

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=- · 02-23-2018

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

GOLDCYLON · 02-23-2018

Quote:

Originally Posted by -=Jeff=-

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=- · 02-23-2018

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=- · 02-23-2018

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 · 02-23-2018

Quote:

Originally Posted by -=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..

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=- · 02-23-2018

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

XfireZ51 · 02-23-2018

Quote:

Originally Posted by -=Jeff=-

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=- · 02-24-2018

Quote:

Originally Posted by XfireZ51

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 · 02-24-2018

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

16080211 for the 90 LT5

16022621 for the 84-86 L98

02-23-2018	#1
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,152	Electronic Spark Module ... future MY 90 Achilles Heel? 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 __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by XfireZ51; 02-23-2018 at 10:50 PM.

02-23-2018	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,131	Re: Electronic Spark Module ... future MY 90 Achilles Heel? Yep.. Another thought is run 1991 ECM Code (repin the ECM) and figure out the key module then run the 1991 ESC.. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-23-2018	#4
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,131	Re: Electronic Spark Module ... future MY 90 Achilles Heel? 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 __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-23-2018	#5
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,131	Re: Electronic Spark Module ... future MY 90 Achilles Heel? 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.. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-23-2018	#7
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,131	Re: Electronic Spark Module ... future MY 90 Achilles Heel? Yes.. biggest challenge will be to get the power key to function.. but I think it is doable __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-24-2018	#10
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Electronic Spark Module ... future MY 90 Achilles Heel? 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 16080211 for the 90 LT5 16022621 for the 84-86 L98 __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.