Before spending money on tools you would seldom use is first determine if you need to do the VATS security PCM to BCM relearn process
You could try this or check to see for your car what the process is

If you open the drivers' door, look on the dash and see if the security light correctly flashes as it should or stays on

IF not that says the security code between the 2 are not matched as happens when changing the PCM

Most cases the process is with a fully charged battery need to do the relearn process which takes just over 30 minutes, and you need to do this correctly so use like a stop watch or other timer

(All other electronics OFF, door closed, etc so they are not dragging the battery voltage down)

with ign key ON but engine OFF, for

1. Exactly 10 minutes
2. Turn key off for 5 seconds

You're going to do this 3 times, so that is just over 30 minutes
By 3rd cycle, the security light should begin flashing to show PCM and BCM are now in sync as to the security seed code. May then trip a VATS error code

Some GM vehicles GM uses 10 seconds rather than the 5 seconds
You cannot guess on those times as GM does not make it easy if someone is trying to steal a vehicle
so by sure 10 minutes on and (either 5 or 10 seconds off)

Else, do a search and find what GM process used for VATS relearn for your vehicle

 

How is it working on the keyless system?

 

Press the start button till going into ACC mode

 

If talking about push button ignition, you hold the button without pressing the brake until the car turns on (assuming the 2007 STS works the same as newer cars). That is the equivalent to turning the key to 'Run'.

 

Hello I just replaced a ecm on my 06 sts 3.6 and I did the relearn an the security light is gone says nothing about theft starting but car will crank but no spark ir sounds because when I sprayed starter fluid it still don't even fire does this mean i have to do the relearn?? An yes the ecm was programmed to my exact Vin number . I thought as long as the security light shut off an the starter cranks the relearn was a go can someone provide some info on this for me

 

What was the reason to think PCM was bad ?

Most common is when driver's door is opened, the security light flashes, when the door is then closed the light goes off
When starting light should stay off

Have you checked for any DTCs tripping ?
Check for any sensor not connected to its wiring connector or not firmly connected or
some fuse not in or blown

You sure this is a new PCM ?

Make sure that when connecting the wiring loom connectors onto the PCM that none of the male or female pins did not get pushed backwards or bent and the pins are clean

Do you have an OBD-II scanner that reads what the VIN # it reads from the PCM and matches your VIN # ?

As to relearns, once the engine is running, a crank position relearn might be needed so that PCM syncs up to the CPS, if not in sync the engine will run poorly and trip misfires

If engine runs OK, need good 5 plus minutes at idle and then turn A/C on at idle for another 5 plus minutes and let PCM relearn that
Then drive nicely for like 10 miles (no WOT) and let PCM learn all non WOT conditions and auto tranny shift points
May take a few drive cycles for all up and down shifts to get learned

 

An the pcm is new from ecm company an was programmed to my exact Vin as well

 

I got into a front end accident car wasvstill running an once I went to pull the radiator support out something got over grounded an fried the ecm. Cause then it wouldn't start again an I kept getting p0103 and po102 maf circuit to low and to high but since new ecm no more codes or check engine light just cranks and don't fire. An the battery is literally brand new ot has gas fuel pump oss turning on an theirs pressure in the fuel line. Sounds like theirs no spark an I'm coming to that conclusion because even with a shot of startervfluid won't even fire us for a second. An I've checked all fuses relays. I just didn't know if the relearn wasn't successful but I thought as long as the security light turned off an the starter cranks then it was a good relearn sorry for the story just trying to give u every piece of info so u can rule our all these other issues . Please help lol thank you

 

So before connecting a new PCM did you fix what wires that had been ripped up ?
Could be one is a ground wire

Again, have you checked to see if any DTCs tripped after trying to crank/start ?

Check fuses like for the MAF, coils, 2 fuses for the PCM, etc ?

You could take one of the sparkplug leads off,

hold that end close to exhaust pipe and have someone crank the engine and see if any spark,
watch your hand and best is when it is darker outside to see the spark

 

You need to crosscheck that to assure the PCM is correctly flashed for your model/year, engine, etc

 

It was done by flagship one I gave them the Vin number an triple checked it to makesure i copied it correctly so but I'm going to take a few picks of the damage done from the accident maybe I'm missing something that you might notice I iver looked because I had a few cruddy body grounds with I cleaned up with a wire wheel an drill that's why I'm ag such a lost the car ran after the accident then once I pulled the radiator support out then it hasn't ran again since but I look forward to your reply thank you again for your help it is greatly appreciated

 

The ecm is opening the injectors I had my obd 2 scanner hooked up and was watching the data an is was showing when I was hitting the key the injectors were opening an closinf

 

What PID were you monitoring ?
Was it the fuel injectors pulse width PID ?

Why you need to debug at the fuel pump relay fuse is good and to see if PCM is not commanding fuel pump on

You check you're getting 12 volts to coils, and did you do as i mentioned to crank with a sparkplug lead shorting to exhaust to see if coil is causing spark to jump to ground (exhaust) ?

 

Didn't get to the sparkplug because I have no one home to start the car while I hold it to see if it's doing what u said

 

Do when you can to tell if PCM is commanding coils on/off would tell you if spark is an issue or not

Again do not shock yourself, use a glove and hold further back of the sparkplug wire and boot of wire for sparkplug allows the spark to jump to ground

 

Ol now here's something interesting the po102 code just came back on saying low circuit I just got a. Now jump starter an was trying to start it qell now this makes things interesting because I had to put a different air intake on it from Mt sisters old cts because my air ckraber was smashed on the accident. I'm taking pictures now an sending u what's exactly going on because I'm so lost now that this code just came back

 

Well that changes the whole issue
You may have blamed your PCM and swapped it when it was not the problem

Exactly what parts of intake did you swap, a photo just showing what was changed ?
Was MAF part of that swap or the throttlebody ?

 

An I had to cut that support out because if was so mangled I couldn't get the radiator back far enough to get the air cleaner straight am the duck tape again is being used to just add extra seal as again the air cleaner box I'm using is from a cts not sts

 

An the picture of the wire was the only wire that I could see any physical damage to as it seen I've pulled back the casing trying to inspect every wire but now that the maf code just came back idk WHT I'm missing cause now that's making me see I've missed damage wires somewhere still but I can't spot any an I've used test lights

 

Ifbu needs more or other angles I'll grab them ty so much for the help

 

You cannot do what you did as to the splices for MAF wires

MAF output puts out frequencies from 0 to about 15,000 Hrz
The more airflow the higher the freq is and PCM uses that than to determine how much to command injectors on

Those spices are adding resistance and screwing up the output to PCM
Also, the IAT sensor uses resistance values change as temp changes and sends that to the PCM to know what the air temp is

If backfeeding like you did, you could have used a sewing needle stick in slightly to touch stranded copper

BUT what you need to do is disconnect the wiring connector and using meter probes to the connector
pins of the wiring connector and would be able to test all wires except for the output of MAF

I ask questions, and you miss answering them, such as where do the wires go ?
Directly back to the PCM or down and where the crash is ?

 

Yes when I had it hooked up earlier to the old scanner in the view chart mode when I was cranking numbers were coming up next ti the massairflow I noticed this when I told u about it showing the injectors opening up an I'm sending u a Pic of my fuse box lay out only thing that says voltage check is right about an next to the massbair flow sensor sorry to sound Un educated on this but electrical isn't my strongest suit but I'm checking that fuse now if there are any other fuses I should be looking at let me know but I wentvup an down the whole box an I found nothing dead besides the ignition coils which is cause the car wasn't being syatyed at the time because it cranks an cranks an just barely syatys an dies

 

You can test with key on, engine off, to see if the MAF is getting voltage with connector off the MAF
and then with test meter black probe to black pin and red probe to the connector pin of pink wire

 

They go down to were it was smashed an then run under the the radiator support an then leads back up in the direction of the ecm

 

I checked the voltage fuse it s hot both sides

 

Pink wire is dead an so is maf fuse

 

Was that test with ign key ON but engine off, must do that for voltage to be hot

Well if you replace the fuse does it blow again and if not do you know have voltage at wiring connector of pink wire pin ?

 

Was that test with ign key ON but engine off, must do that for voltage to be hot

Well if you replace the fuse does it blow again and if not do you know have voltage at wiring connector of pink wire pin ?

aquarium q
With a new fuse still dead an ignition is on engine oa

GM is not common to use a gray or tan wire for voltage, normally use red or like pink

TAN and gray I think is IAT ?

OK pink wire isbhor again checking ground now that was the wire that was dead from the beginning checking the a now

 

Just tried starting still not starting an then the po102 code came back low circuit like I'm so confused the connector is good an being powered why would I still keep getting low circuit issues then

 

Low I think means PCM not getting output from the MAF on yellow wire

 

aquarium q
With a new fuse still dead an ignition is on engine oa

OK pink wire isbhor again checking ground now that was the wire that was dead from the beginning checking the a now

If still no voltage at MAF connector, than a wire is cut in two

OK an the ground is live now to so the black wire is grounded an pink wire is showing voltage why is still not staying then

What is not staying on ?

 

If still no voltage at MAF connector, than a wireI is cut in two


What is not staying on ?

No there is voltage now the pink wore is good the ground is good everything is hot and working but it still won't start an the electric start works also which I know if their codes it won't work that's why again I fell it's nit getting spark

 

You have not posted what MAF PIDs your scanner supports

This is an aprox guess when cranking engine

MAF in pounds/min 1 lb
MAF output Freq about 3,000 Hrz or less
Maf in grams a second, about 6-8 grams

MAF Lbs	MAF Freq	MAF grms
1	3062	7.83

 

You have not posted what MAF PIDs your scanner supports

This is an aprox guess when cranking engine

MAF in pounds/min 1 lb
MAF output Freq about 3,000 Hrz or less
Maf in grams a second, about 6-8 grams

MAF Lbs	MAF Freq	MAF grms
1	3062	7.83

How would I be able to tell that?? All I seen was numbers going up next to the maf on the view chart option I have an obd1 1/2 ,2 code reader how would I be able to give u the correct info u need? Or better WHT do I need to do exactly to provide u with the correct info ?

 

You might have to take off that flex covering of wires down in that smashed area and really follow the yellow wire
from the MAF to that area
Wire could be cut under the wire covering or where all that black tape is

 

You might have to take off that flex covering of wires down in that smashed area and really follow the yellow wire
from the MAF to that area
Wire could be cut under the wire covering or where all that black tape is

View attachment 660205

OK I got thr mag to acknowledge the ocm thr of scanners gas picked it up still won't start ivr checked ots getting spark thr fuel pump I'd kicking on an the battery is charged an I put a jump starter on that also an still it's not firing

 

Also, if you still have your old PCM, swap that back in and try a start to see if the new one is adding to the problem

 

OK sorry I never got a notification you responded bit yes yellow wire is good the maf is showing numbers on the obd view chart setting and yes I'm getting spark I had a old coil from a tune up that I connected an stuck a spark plug in it an helf it to the block an seen spark very good spark also I only did that for one cylinder I didn't test them all but I'll switch the ecms now an let u know what happens because right now the check engine light is off all the wires on the maf are good all the fuses are good and the fuel rail has gas an I climbed under the car an did the remote start an heard the fuel pump prime an kick on and I also have a half tank of gas but let me do this ecm switch quick an try starting be back in 20

 

I had you swap PCMs as a testpoint
The old PCM stored the VATS security code in flash memory so IF there was a problem with the new PCM as to the relearn for VATS than the old one having the code would have started the engine

Since it did not than it pretty well says VATs not the issue

That leaves all my posts saying to test fuel system

Fuel rail can have gas, but you do not know what the fuel rail pressure is and those injectors work either around 43 or 58 PSI (depending on the fuel design for that car)

You have to get on this, as I posted, are the injectors getting 12 volts ?
Using a noid light to one injector wire loom connector and see if the light flashes during cranking ?
Connect a fuel pressure gauge to the fuel rail and during cranking see if normal PSI is seen ?

Have to test the fuel system relay as I showed, can even jumper relay and see if engine than starts

Other than that than there is some other wires damaged

 

I had you swap PCMs as a testpoint
The old PCM stored the VATS security code in flash memory so IF there was a problem with the new PCM as to the relearn for VATS than the old one having the code would have started the engine

Since it did not than it pretty well says VATs not the issue

That leaves all my posts saying to test fuel system

Fuel rail can have gas, but you do not know what the fuel rail pressure is and those injectors work either around 43 or 58 PSI (depending on the fuel design for that car)

You have to get on this, as I posted, are the injectors getting 12 volts ?
Using a noid light to one injector wire loom connector and see if the light flashes during cranking ?
Connect a fuel pressure gauge to the fuel rail and during cranking see if normal PSI is seen ?

Have to test the fuel system relay as I showed, can even jumper relay and see if engine than starts

Other than that than there is some other wires damaged

Hey OK I'm gonna go rent the tool to check the fuel pressure today I had another question though at the beginning of this ordeal my father felt I may had flood the engine way back when this issue started an he said take out the spark plugs to see if there was gas in the cylinder. So I did and there wasn't but I guess this is a common issue for the 3.6 having oil in the spark plug well an whenvi took out the spark plug it was drenched in oil. So short answer when I tested for spark I just took a sparkplug I had kicking around the cellar to check it quickly but I didn't check the actual spark plug from the engine( yes,yes, I know stupid mistake) but the oil in these wells be making it so the isn't starting. My father says he feels that wouldn't cause that because the oil is in the well but I'm just trying to let you know of any other issues going on at the moment to see if they could be a factor

 

One slight possibility is that it may have jumped valve timing when the wreck happened or after. Check compression on all cylinders. Valves opening and closing at the wrong times will show up as crazy compression numbers. Probably not but just spitballing here ).

Both the 3.6 and the N* are interference engines. Good Luck.

 

Have to find than what function or sensor is not working by likely wiring damage

Do these during cranking

1. PCM will not allow startup if seeing no oil pressure building up
2 Must do with OBD-II scanner, best is scanner in record mode so can replay back and not missing seeing data in a scan only
3. Check all engine PIDs scanner allows, crank or CAM sensors, looking for any sensor not showing a valid number during crank, including the IAT which is part of the MAF as I am not convinced the 5 wires of MAF connector is fixed and air temp is required

4. Check timing during cranking, the PCM calibration is deciding how much timing but 2 sensors reporting and that is what RPMs and MAF output in grams

This is an example of calibration for a 3.6L engine, and you cross grms and RPMs and at that meeting point is what PCM commands as to timing value

See if during crank the timing meets those 2 feedback sensor points as example
when grm/cyl is 0.12 and RPM is 600
than commanded timing would be 22.5 degrees

 

OK guys sorry for the delay so I replace s all 6 spark plugs was grasping at straws to try anything car would still not starting sounded like no ignition. Then I tried this morning an it started to crank an semi start an die so I was disconnecting the jumper cables an I see a piece of wire casing I went to grab An the I noticed wires running down along the side of the engine I hadn't checked an then I cam across the crank sensor I believe has a heat shield around it an I looked up a Lil further an noticed the wires to that were serverly burned in spot but then I moved the wire an I finally found the broke. Wire!!!!!!! I believe I've been searching for the 2 wires that run to the crank sensor were literally broke parallel to each other. Which makes sense why is started to try starting today cause those 2 wires run up to the middle coil an I was moving those around yesterday to cha ge the plugs. I'm very excited I believe I finally solved the issue but going to the doctors now I'll be back in touch later but I'm very sure this is the issue. Cause the car was just barely starting an the. Dying but It was semi firing if you could call it that but I'll come back later and let you know but now it makes perfect sense why it didn't start but the wires weren't completely cut in half just the casing to them both broke which has been making them touch each other which is why I believe I was never getting a code for crank sensor but I'll let u know layer WHT happens ty again for all ur help

 

Hello sorry I haven't been back in touch so I thought the crank sensors wires fix e d rhe issue which they did for few days now there was another short between the cam sensors the I dnr kniw what it's called but it's the part in front where the 6 tan wires come together an break down into 3 wires. And stupidly I cut it open without take a picture ro remember how rhe wires went an not I can't figure out how they connected in the casing. Could someone please help with a Pic of this piece cut open with the wires showing how they connect or could someone tell me which wires connect to b what cause I've been at it for hours and now luck. Please a de help thank you again