Hey guys, I just put a set of MAC Headers, removed AIR pump, Converted to electric waterpump, and rebuilt the tranny. As soon as I started my car, Service light came on along with ABS INOP light and airbag light. I thought the service light was the airpump until I got it tuned out of the PCM by PCMFORLESS. That is when he told me my car has code 43 which is Knock sensor circuit and the car is losing 9 degrees of timing. What could be causing all this? Has this happened to anyone else? Any help is appreciated. Thanks, Tom.

 

DTC 43 sets when the PCM doesn't "see" the knock sensor. When that happens, the PCM defaults to an algorithm that pulls timing under virtually ALL circumstances.... up to 15-degrees.

Either the KS is bad, the harness wire is bad or the connector is off the sensor.

 

The ABS inop could be due to the lamps in the third brake light being out. For the air bag, start with checking the fuse (#1) in the IP fuse panel on the end of your dash.

 

The third brake light works fine, and the #1 fuse is good also. What else could it be?

 

The ABS and Air Bag get their ground from the ground post located on the passenger side fender, next to the red plastic positive terminal. This ground is famous for getting dirty and causing a "light show". Disconnect the negative on your battery, remove the wires from your ground terminal, remove the ground stud and scrap away the paint from under the ground stud. Clean the ground stud and reassemble.

 

You installed headers... make sure your knock sensor wire didn't get melted

 

I'm gonna check that out now. I'll let you know. Thanks

 

I checked the wires for the knock sensor. They were close but the insulation was not melted. I put the stock knock module and that didn't fix it either. I think i'm just gonna replace the knock sensor and see what happens. Thanks, Tom

 

OBE1 95Z28 : Thanks for the info, your advise fixed my ABS and Airbag lights. Thanks, Tom

 

Its EXTREMELY easy to check the KS and the wiring. Pull the connector off the KS, key "on" and probe from the harness connector pin to the block. Should be +5V. If it isn't you have a wiring problem. Then with the connector still off the KS, probe from the single pin on the KS to the block. Should read 4,500 ohms, +/- 1,000ohm. If it isn't the KS is bad or the ground it bad.

Put the connector back on the KS. Probe from the wire to the block, should read 2.5V.

Or you could use the Mr. Goodwrench approach of "let's try replacing parts until we find the one that was bad."

 

zmanlt1,

Glad the ground fixed part of your issues! That's the power of this board, sharing info!