Random stalling

[hookedup50]

I was on another thread earlier, and stopped power probing and started wiggle test. The truck started with click of starter and stalled 5 seconds later. I wiggled around ECM again and it started again for 5 seconds. Now nothing. My ex has my service manual. Is there an ecm diagram for a 97 somewhere in the library?
Thoughts? I’ve got clean grounds, no air in clear tube. Good known pmd. Has anyone had to get a factory cut key? Just brainstorming

 

[hookedup50]

I wish the pin out for ecm was still active 97 Chevy

 

[ak diesel driver]

Is your security light staying on?

 

[dbrannon79]

I know there are diagrams and online service manuals on the DP forum. I can't search for them at the moment but if you still need, I will post up a link later after work.

 

[hookedup50]

The ABS/ anti theft light comes on and shuts off,

 

[Paveltolz]

ECM Ground Locations. Engine Controls Schematic 1997

Working on the ECM Schematics

 

[Paveltolz]

ECM Pin Out Schematics 1997. Have to break them down into parts as a single file is too large.
FWIW, The files say PCM but, we know it as "ECM" semantics, schmantics, Schematics....

 

[hookedup50]

The anti theft light comes back on when cranking. I’ve owned the truck so long , I don’t remember what is normal. In order to get the wait to start light to stay on, I have to fiddle with the ecm wires. Once I have a 10 second wait to start comes on. It started twice today, stalled after five seconds. I think it’s a security glitch, and always have. Pmd and everything is redundant. Multiple extensions and 2 pmd on sink in bumper.

 

[hookedup50]

Thank you for the schematics, has anyone bypassed the security with proper ohm resistance fooler?

 

[Paveltolz]

You might contact Diesel Site to see if they'll do a re-flash on your Heath tune (Diesel Site bought Heath) and delete the security feature.

 

[dbrannon79]

Wasn't there a procedure for the ECM to re-learn the security? can't recall which model it was by I recall something like leaving the key in the run position for something like 10 minutes.

 

[hookedup50]

I did that 10 minute relearn yesterday.. I have another ecm that im sending out for a tune for ATT turbo. I will hook up software today and see if any soft codes appeared yesterday. Is there any reason not to bypass the security system and then do a relearn?

 

[hookedup50]

Wasn't there a procedure for the ECM to re-learn the security? can't recall which model it was by I recall something like leaving the key in the run position for something like 10 minutes.

You have a good memory

 

[dbrannon79]

To be honest bypassing that factory security would be the way to go, later if you want, install a good aftermarket alarm with remote start!

I get spoiled with my remote start on my 95 during the winter LOL

 

[hookedup50]

I’m going to bypass that for good measure, after I get the correct resistor. I put a cheapo scanner and the code says cruise control module failure. I need a new multi switch. The good news is that I have been thoroughly through everything, and repaired issues and potential ones

 

[dbrannon79]

after I get the correct resistor.

Are you taking about the resistor in the PMD? missing one will cause a no start or start then stall condition on the ODB2 units.

the local auto parts sells a dorman brand kit that has two. one that's a #5 and a #9. Part number 904-107

Here is a link to one on amazon for $20

https://www.amazon.com/Dorman-904-107-Calibration-Resistor-Chevrolet/dp/B003SOJVEQ

 

[ak diesel driver]

Missing a resistor on OBD2 will not affect it at all. TD, Turbine Doc, ran his for a year with no resistor to proves Steaksauce wrong. OBD1 will look for the resistor every 50 starts IIRC, It will set a code

 

[Glagulator]

A 97 truck should not have passlock, it started in 98.
With passlock the resistor mod simply bypasses the ignition switch sensor.
Passlock will still be there, and can only be turned off by programming the PCM.
A 97 PCM does not have passlock enabled.

 

[hookedup50]

The locksmith said it did, but I prefer advice from here. Never had bad advice. What part of cruise control has to do with injector pump? I added a simple scanner and found my cruise module is bad, I ordered a replacement multi switch, cause I think it’s in there and the contacts are not good here. Im finding corrosion throughout.

 

[dbrannon79]

I don't think the cruise would effect it, but if it has to do with powers and ground it can possibly backfeed into another circuit causing issues for the ECM. anything's possible.