Code 43 - ZR-1 Net Registry Forums

Subfixer · 08-26-2019

After 1200 miles to and around Carlisle and back, the Z ran flawlessly.
Took it to work this morning and the SES light came on after 55 miles. Did some running around and the light came on as soon as the car got into closed loop.
Drove home with the light on, and about 35 miles from work, the SES light went out. Pulled codes and got 43 (saved code), knock sensor. Drove around some more this evening and no codes popped up.
I'll put the car in the air tomorrow and check the connection. Hope that's all it is.

secondchance · 08-26-2019

About 3 years ago, I had my car on a lift at Jim Voter’s garage. Probably changed oil and whatever service while on the lift. Just visual inspection before bring the car down and noticed knock sensor wire had been completely severed. What was interesting was the car ran fine despite O2 sensor being totally disabled and no SES light! Go figure...

Subfixer · 09-14-2019

Still can't find the reason for my code 43. Did all the checks in the FSM.
Knock sensor resistance is in spec.
Have correct voltage at the knock sensor connector.
Reseated the PROM.
Code 43 is still intermittent.
Typical symptom: drive about 60 miles, stop to get gas, SES light comes on as soon as I restart. Car runs fine, no other symptoms except secondaries won't work while light is on.
If the car sits for a few hours, upon restart, SES light is out and car runs normally.
Any ideas of where to check further?

A26B · 09-14-2019

I had exactly the same symptoms. Went through all the same steps, including replacement of the harness connector. It's an intermittent knock sensor failure.

Replaced & problem solved

Subfixer · 09-14-2019

Thanks Jerry. Just ordered one.

Subfixer · 09-20-2019

Probably the easiest repair I've done to date. Knock Sensor screws into a blind hole in the block. I thought it may have screwed into the water jacket, but it does not.
Will find out tomorrow if my intermittent code 43 is gone.

Next up, removing the radio and receiver from the dashboard. Not looking forward to that job......

QB93Z · 09-21-2019

Quote:

Originally Posted by Subfixer

Next up, removing the radio and receiver from the dashboard. Not looking forward to that job......

Start with the Center Console lid (4 screws on the hinge), then work your way forward. One of the three screws for the shifter bezel is under the forward cup holder. Remove the center, upper AC difuser and then you can get to the radio bezel screws. Keep the screws separated, some are machine screws, some thread into plastic.

Jim

Subfixer · 10-02-2019

After replacing the knock sensor, all was ok for a couple of weeks. Last weekend the SES light came on after the car was warmed up. I could hear some part throttle detonation, then the light came on. Code 43 again.

Subfixer · 10-18-2019

Well, I'm getting nowhere with this problem. Still get intermittent code 43.
New Knock sensor, all checks in the FSM are good.
I removed Mark H's chip, but nothing changed. Put it back in.
No vacuum leaks, no other codes stored. Good fuel pressure.
Car runs great even with the SES light on. Just no secondaries when that happens.

Not sure where to look next.

G8nightman · 10-19-2019

Your chip might be bad. The knock sensor electronics are on it. I had the same problem with mine.

Sent from my iPhone using ZR-1 Net Registry

08-26-2019	#1
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Code 43 After 1200 miles to and around Carlisle and back, the Z ran flawlessly. Took it to work this morning and the SES light came on after 55 miles. Did some running around and the light came on as soon as the car got into closed loop. Drove home with the light on, and about 35 miles from work, the SES light went out. Pulled codes and got 43 (saved code), knock sensor. Drove around some more this evening and no codes popped up. I'll put the car in the air tomorrow and check the connection. Hope that's all it is. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

08-26-2019	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: Code 43 About 3 years ago, I had my car on a lift at Jim Voter’s garage. Probably changed oil and whatever service while on the lift. Just visual inspection before bring the car down and noticed knock sensor wire had been completely severed. What was interesting was the car ran fine despite O2 sensor being totally disabled and no SES light! Go figure...

09-14-2019	#3
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Re: Code 43 Still can't find the reason for my code 43. Did all the checks in the FSM. Knock sensor resistance is in spec. Have correct voltage at the knock sensor connector. Reseated the PROM. Code 43 is still intermittent. Typical symptom: drive about 60 miles, stop to get gas, SES light comes on as soon as I restart. Car runs fine, no other symptoms except secondaries won't work while light is on. If the car sits for a few hours, upon restart, SES light is out and car runs normally. Any ideas of where to check further? __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

09-14-2019	#4
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Code 43 I had exactly the same symptoms. Went through all the same steps, including replacement of the harness connector. It's an intermittent knock sensor failure. Replaced & problem solved __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

09-14-2019	#5
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Re: Code 43 Thanks Jerry. Just ordered one. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

09-20-2019	#6
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Re: Code 43 Probably the easiest repair I've done to date. Knock Sensor screws into a blind hole in the block. I thought it may have screwed into the water jacket, but it does not. Will find out tomorrow if my intermittent code 43 is gone. Next up, removing the radio and receiver from the dashboard. Not looking forward to that job...... __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

10-02-2019	#8
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Re: Code 43 After replacing the knock sensor, all was ok for a couple of weeks. Last weekend the SES light came on after the car was warmed up. I could hear some part throttle detonation, then the light came on. Code 43 again. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

10-18-2019	#9
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 382	Re: Code 43 Well, I'm getting nowhere with this problem. Still get intermittent code 43. New Knock sensor, all checks in the FSM are good. I removed Mark H's chip, but nothing changed. Put it back in. No vacuum leaks, no other codes stored. Good fuel pressure. Car runs great even with the SES light on. Just no secondaries when that happens. Not sure where to look next. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige Last edited by Subfixer; 10-18-2019 at 08:01 PM.

10-19-2019	#10
G8nightman Join Date: Dec 2007 Location: NYC Posts: 1,188	Re: Code 43 Your chip might be bad. The knock sensor electronics are on it. I had the same problem with mine. Sent from my iPhone using ZR-1 Net Registry __________________ 90 Chevy ZR1 LPE #2315 'SOLD' 90 Chevy ZR1 LPE #2774 'SOLD' 91 Chevy ZR1 Callaway aerobody 91 Chevy ZR1 #1512 91 Chevy ZR1 #951 95 Chevy ZR1 #338 'SOLD' 91 BMW 850i 94 BMW 850csi 95 BMW 850csi 94 Lotus Esprit S4 07 Benz CLS550 06 BMW M5 "SOLD"