Code 43 - ZR-1 Net Registry Forums

jdodds1111 · 06-26-2005

Hi All
I have managed to get and fit a Knock Sensor.
It still will not bring in the second throttles and injector also returns Code 43 (Knock Sensor signal).
Using the standard circuit diagrams 90 through 92 the Dark Blue Knock Sender wire goes to B20 (Red 20) but on my ECU B20 has a rubber bung and no wire (checked if it had snapped off but no joy). the only other dark blue wires are C7 (Green 7 A/C Status) and D7 (Green 7 Pass Key Signal). D7 has a ref voltage of 5 volts so I tried it but with no result. The new sensor made no differance.
I am wondering if early LT5 ECU's use a stand alone Electronic Spark Control Module were as the later were integral and the Knock Sensor went straight to the ECU.
Has anyone got a 1990 circuit diagram for the Knock sensor.

John Dodds
Lancashire
England

06-27-2005

There is a connector over on the passenger side of the vehicle by the windshield wiper fluid resevoir that is part of the ESC ssytem.

Do you have a cut/nicked wire?

John, I will also look in the book when I get home from work.

06-27-2005

So far based upon your description, you are going about it correctly.

The next step is to check the ohms between the sensor terminal and engine block. SHould be between 3300 and 4500 ohms.

Since you have replaced the KS, I would venture to guess your last chances are:

Harness/connector issues
Bad Mem-cal
Improperly seated mem-cal

jdodds1111 · 06-28-2005

Thanks for That

The sensor bells out at 99 ohms on the wiring at the ECU. Which is what I measured when it was taken out of the box and the same value as the old sensor.

threestar40 · 07-14-2005

I have been getting code 43 as well for a long time now.

I put a new knock sensor in last weekend and it seemed to work, My knock sensor had bad resistance as Jeff described. I was only getting when the coolant got to 97 celcius because that is when the car runs the test. It is kind of difficult to chase this one down. I read all about it in the factory service manual...I can tell you more if you want. I think the knock sensor fixed my car, but I'm not for sure, I know I have gotten it hot since I put it in and no code has been set.

If you only got 99 ohms, your knock sensor is definitely bad or you got the wrong one. I would be happy to help you with what the factory service manual says about it if you want. Maybe I can learn something from you as well.

threestar40@mindspring.com

I only came here to see Jeff's avatar

I am usually at the corvette forum. I need to come here more, but I just can't get used to it and don't have time to read both.

Rick =)

Z Factor · 07-15-2005

Quote:

Originally Posted by threestar40

I only came here to see Jeff's avatar

I am usually at the corvette forum. I need to come here more, but I just can't get used to it and don't have time to read both.

Rick =)

Well Rick it is a start. Dave and I are trying to find different ways to make this forum more appealing to the ZR-1 community. Having guys like Jeff post here is a step in the right direction. I suspect the single biggest reason people go to CF instead of here is the volume of posters there. If more of us check in here per day, we can turn that trend around. I like the CF and will still go there as well, but we hope more ZR-1 owners will spend time here amongst friends.

JIM

06-26-2005	#1
jdodds1111 Join Date: Jun 2005 Location: Lancashire England Posts: 6	Code 43 Hi All I have managed to get and fit a Knock Sensor. It still will not bring in the second throttles and injector also returns Code 43 (Knock Sensor signal). Using the standard circuit diagrams 90 through 92 the Dark Blue Knock Sender wire goes to B20 (Red 20) but on my ECU B20 has a rubber bung and no wire (checked if it had snapped off but no joy). the only other dark blue wires are C7 (Green 7 A/C Status) and D7 (Green 7 Pass Key Signal). D7 has a ref voltage of 5 volts so I tried it but with no result. The new sensor made no differance. I am wondering if early LT5 ECU's use a stand alone Electronic Spark Control Module were as the later were integral and the Knock Sensor went straight to the ECU. Has anyone got a 1990 circuit diagram for the Knock sensor. John Dodds Lancashire England __________________ Using an LT5 1990 fitted to an Ultima GTR and Porsche Box

06-28-2005	#4
jdodds1111 Join Date: Jun 2005 Location: Lancashire England Posts: 6	Thanks for That The sensor bells out at 99 ohms on the wiring at the ECU. Which is what I measured when it was taken out of the box and the same value as the old sensor. __________________ Using an LT5 1990 fitted to an Ultima GTR and Porsche Box

06-27-2005	#2
Jeffvette Guest Posts: n/a	There is a connector over on the passenger side of the vehicle by the windshield wiper fluid resevoir that is part of the ESC ssytem. Do you have a cut/nicked wire? John, I will also look in the book when I get home from work.

07-14-2005	#5
threestar40 Join Date: Jan 2005 Posts: 150	I have been getting code 43 as well for a long time now. I put a new knock sensor in last weekend and it seemed to work, My knock sensor had bad resistance as Jeff described. I was only getting when the coolant got to 97 celcius because that is when the car runs the test. It is kind of difficult to chase this one down. I read all about it in the factory service manual...I can tell you more if you want. I think the knock sensor fixed my car, but I'm not for sure, I know I have gotten it hot since I put it in and no code has been set. If you only got 99 ohms, your knock sensor is definitely bad or you got the wrong one. I would be happy to help you with what the factory service manual says about it if you want. Maybe I can learn something from you as well. threestar40@mindspring.com I only came here to see Jeff's avatar I am usually at the corvette forum. I need to come here more, but I just can't get used to it and don't have time to read both. Rick =)