After getting my TPI swap running on a 400 block into a Caprice Wagon, I'm throwing a consistent Code 43 within seconds of startup. I've cleared codes a few times to verify that it keeps popping up. Knowing that it takes about 4 seconds of low voltage to the sensor module to trigger a code 43, and the service light comes on about 4seconds after start, it's fairly obvious I have a signal problem to the ECM. What's the next step to trace it?

Secondly, Using TunerRT Pro, I finally got my first look at running the dash board feature after figuring out what port it was connected to. I have it set up to look at RPM/25,(picked the wrong one first time) Map Kpa's (surprised to idle at 30-40) BLM (main)BLM integrator .and pulse width.

I could see RPM and Kpa's chnaging but it seemed the BLM's were unchanging at 128. NO WAY! Is it likely that I was not yet in closed loop and open loop blm's were locked at !28?I'm concerned that my BLM's were not moving at all.

Also it may be important to add that when I open up the ALDL FLAGS section of TunerRT, Ii see several red entries: KS OFF, improper shut down, Learn enable is DISABLED, non-volatile memory BOMBED.

I'd also like suggestions of setting up the dash feature as to what six functions are best to observe.

 

I left this post several months back. Is there anyone who can answer part of my questions?

By the way, I'm running a 730ECM. it seems the ESC module is an integral part of it and not an isoloated modukle. IS this correct? Any pin out diagram of the 730 shows a direct connection from ECM to knock sensor with no "module" in between.


I'd greatly appreciate knowing what six funtins are most useful to set up on the TunerRT Pro dashboard. obviously: rpm, Kpa and what four others BLM's ? knock counts? Two more.
Dave Buchholz, Rochester NY

 

As far as the indicators go...
KS OFF
Knock sensor not used yet because differential coolant temperature has not crossed its threshold setting.
improper shut down
Never got a clear answer on if this bit is "true" or "false" normally.
Just edit it to the opposite if it seems incorrect.
Learn enable is DISABLED
You are not in closed loop. BLMs will not move if learn is disabled.
non-volatile memory BOMBED
Same as above item, Never got a clear answer on if this bit is "true" or "false" normally. Just edit it to the opposite if it seems incorrect.
No ill effects either way.

Dashboard display is what you want to see.
No defined "set" that works for everyone.
If you are driving while watching (not recommended of course) use as few as possible that are large on the screen.
If reviewing data from logs then you may want as many items on the screen as can fit.

Check your knock sensor again, could be part of the root cause of your 43.
Jp

 

Checking resistance of sensor. Gm book says normal is between 33k to 45k I get 99k from terminal inside sensor to block.

Can't get a solid reading on wire from sensor to ECM Headed to Advance Auto to test afew out of the box. Checking pin outsd to ensure correct wires in play.

 

The 350 KS should be 3.9K from pin to ground (housing)
You may have bad connection if you used teflon tape or heavy sealer.

 

Although Ii haven't gotten to figuring out why I get 99K ohms on the sensor yet, I did find a wiring problem.

In the harness, at a point about three feet from the sensor a crimped connector came apart. It is now a soldered connection instead. I've cleared codes and will refire this morning. No exhaust system.. too late... too loud.

Later today I'll report back.The big project that this was part of, was hanging new headers. had an issue of burning out gaskets. NO flex in a very short system out to side pipes kept prying the headers away from the block. burned out three sets in a matter of weeks Had new headers ground flat at the block flange and will use flex couplings at the pipe flanges.

JP thanks for the info.. will check on the "flags" mentioned last report later today.

 

A 99K (100K nominal) knock sensor is used on the MAF based TPI cars along with TBI cars. Get one for a '92 Firebird 5.7L TPI engine.

RBob.

 

Many thanks for that response! After fixing the wire, you can guess correctly that I was seeing a knock senor Code 43. Will grab a new senosr as suggested, and take a meter with me to be sure I get the coirrect one. Thanks again.

 

have similar problem....when you all say check resistance from sensor to block do you mean one of the dmm terminals connected to knock sensor and other to the engine block???