Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
Ciadella InteriorsAmerican Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Octane LightingNu-Relics Power Windows
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy

LMC Truck



Username Post: 2000 Silverado ECM Change        (Topic#347110)
crazycoyote 
Forum Newbie
Posts: 21

Reg: 01-10-15
09-12-17 03:20 PM - Post#2707500    

If I replace my ECM w a used one w the same part number, what has to be done to program it?



 
LMC Trucks
jktucker92 
Silver Supporting Member
Posts: 68
jktucker92
Reg: 02-05-17
09-13-17 07:07 AM - Post#2707551    
    In response to crazycoyote

The program has to be loaded into the ECM using a flash programmer. The easiest way to do this is at the dealer. They may have the ability to program it out of the vehicle, but I've never asked. In general, they program it while it's in the vehicle, and I think the charge is $75. There are a few flash programmers out there that can be purchased, so there may be others that can program it around you (I have one).
There are lots of parameters stored in the PCM, that define a vehicle. Many of those parameters are similar from vehicle to vehicle for the same engine. Some parameters will be so different that the engine won't run (such as the difference between a V6 and V8), but others would be just a nuisance (such as the gear ratio for the speedo, and lockup points on the torque converter). If the PCM came out of a vehicle with the same engine and transmission, the truck may run without reprogramming. You should still have it programmed, but it may allow you to drive it to the dealer.



 
crazycoyote 
Forum Newbie
Posts: 21

Reg: 01-10-15
09-13-17 05:54 PM - Post#2707603    
    In response to jktucker92

Thank you for the information. I have been told and saw on youtube where after a ECM change they had a no start condition and after a sequence of key on and off for different times it would then start. Trying this with mine did not work. It came off a 99 Suburban or Tahoe with a V8. The part number was the same. The only difference I can see would be possible gear ratios as you described.



 
jktucker92 
Silver Supporting Member
Posts: 68
jktucker92
Reg: 02-05-17
09-14-17 08:35 AM - Post#2707633    
    In response to crazycoyote

I don't think replacing the PCM requires the VATS relearn procedure. That would be required to replace the BCM or ignition lock, but I don't think PCM is part of the relearn. It's a lengthy process that takes ~ 45 minutes to complete. If it is a VATS problem, then your security light should show a problem.
You mentioned that the new PCM came out of a '99 Suburban. Is your truck a diesel? If it is a diesel, then I'm not sure why it won't start. The diesel PCM should be the same from '97 to '00 since it's the same 6.5L motor.
If it's a gas motor, then the PCM is different between a '99 Suburban and a '00 Silverado. The Silverado Gas motors are the newer LSx variant motors (4.8, 5.3, 6.0) and the '99 Suburban uses the old 5.7L that is a completely different motor and requires a different PCM. Should be PN 9354896



 
rockfangd 
"4th Year" Gold Supporting Member
Posts: 2154
rockfangd
Age: 31
Loc: Utica ny
Reg: 04-13-10
09-14-17 05:56 PM - Post#2707671    
    In response to jktucker92

I am pretty sure reprogramming is necessary as the vin information will not match

Old School GM fan FOREVER


 
1983G20Van 
Super Senior Member
Posts: 3627

Loc: Bedford, Texas, USA
Reg: 11-13-02
09-15-17 03:37 PM - Post#2707745    
    In response to jktucker92

  • jktucker92 Said:

If it's a gas motor, then the PCM is different between a '99 Suburban and a '00 Silverado. The Silverado Gas motors are the newer LSx variant motors (4.8, 5.3, 6.0) and the '99 Suburban uses the old 5.7L that is a completely different motor and requires a different PCM. Should be PN 9354896



NOT completely accurate. The OP never said what engine he has. I have personally reflashed a Black Box PCM in a 2000 GMT800 with the 4.3 V6 to swap the truck from a 4L60E to a 4L80E. It very well could be the correct PCM, but the wrong flash.

ALSO some of the bigger trucks the C3500s carried on as the GMT400 body style into 1999 and 2000. I know you could get a 2000 Tahoe that still had the same 5.7. Hell in Mexico you got the 5.7 in a GMT800 with the 5spd behind it, even in a GMT800 2002 Tahoe.

1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


Edited by 1983G20Van on 09-15-17 03:40 PM. Reason for edit: No reason given.

 
crazycoyote 
Forum Newbie
Posts: 21

Reg: 01-10-15
09-16-17 04:50 AM - Post#2707800    
    In response to 1983G20Van

My 2000 Silverado has the 5.3. 1999 was a changeover year where they built both. My pcm and the one from the Suburban are both part # 09354896. with the one from the Suburban my truck cranks and gives an occasional kick like it might start but won't. I put my old one back on and truck starts but im sure it will still run horrible part of the time as it has been doing. I am thinking its in the pcm as i get no codes. I have changed fuel pump and checked pressure and regulator. I changed coolant temp sensor and the mass airflow sensor. Truck starts hard then spits and sputters and may stall. then it will drive fine until all of a sudden it will have no power and will spit and sputter again for a moment and then all is fine again. It has been scanned with both an OTC and a Snap ON scanner . Thanks for the help. It might be time to shoot the old horse



 
2plus2 
Member
Posts: 1042

Loc: Langley,BC
Reg: 02-03-05
09-16-17 11:49 AM - Post#2707828    
    In response to crazycoyote

If the suburban was a 99 with a 350 then there is no way it will work
The 350 has a different firing order then the 5.3
Not to mention the 350 has a distributor and the 5.3 has 8 individual ign coils
Part numbers mean jack,its what firmware is loaded onto the PCM


69 Canadian Pontiac 2+2
factory L48 350 Chev,TH350,PW,PT
99 Silverado RCLB 4.8 NV4500 14BSF 4.10's locker 6" Procomp 35 bfg m/t's 9k winch cutout flares
07 Town Car Loaded,Tinted,Getting Bagged


 
jktucker92 
Silver Supporting Member
Posts: 68
jktucker92
Reg: 02-05-17
09-18-17 07:50 AM - Post#2707997    
    In response to 2plus2

Since the PCM is the correct PN, it should work for your application with the correct program in it. However, I'm not aware of any '99 Suburban that had the 5.3L engine, since a '99 Suburban was a GMT400 truck and would have had a 5.7L gas, 7.4L gas, or 6.5L diesel engine. Yes, '99 was a transition year for the trucks, but I believe all Suburbans were GMT400's. For that reason, I don't think you can be sure what program is in the new PCM. Things can be mis-marked at a wrecking yard, and there are also rare cases where a conversion was done.
The next step would be to flash the new PCM with the correct program for your vehicle. You can either drive it to the dealer with the old PCM (assuming it will get that far) and have them flash it or find some other way to have the PCM flashed with the correct program. I believe there are some online services that can flash a PCM, but I've never used them and have no opinion on the service.



 
crazycoyote 
Forum Newbie
Posts: 21

Reg: 01-10-15
09-20-17 08:38 AM - Post#2708224    
    In response to jktucker92

You are correct. My mistake interchange says 99-00 trucks but only 2000 Suburban. I returned to salvage yard to verify and my mistake again as the one I got came off a 2000 Suburban with a 5.3 same as my truck. Since the yard was willing to exchange it I got one from another 2000 Suburban with a 5.3 and 4wd just like my truck except Suburban. Part# 09354896 Once again no start. I will try the relearn again and see what happens. Sure seems like it should just plug and play since engine controls should be the same. I would think it should at least run. Thanks again to everyone for their help



 
wreckmech 
Member
Posts: 191

Loc: Parsippany, NJ
Reg: 10-08-02
09-20-17 06:00 PM - Post#2708298    
    In response to crazycoyote

The ECM is VIN specific. If it sees a different programmed VIN#, it assumes a theft condition, therefore no start. The VIN# relearn procedure took over an hour when I did mine. Make sure you have a battery charger hooked up when you do it.

Turn the key to the run position, no cranking. Leave it on for 25 minutes. Turn it off. Do this 3 times. Don't scrimp on the 25 minutes. If it doesn't start, do it one more time. I had to do mine the fourth time. It then started, and ran fine.



 
rockfangd 
"4th Year" Gold Supporting Member
Posts: 2154
rockfangd
Age: 31
Loc: Utica ny
Reg: 04-13-10
09-20-17 06:58 PM - Post#2708309    
    In response to wreckmech

Agreed.
I mentioned that because I have run into it before.
Not much is plug and play anymore.
Vin info in all modules must match otherwise it will not work

Old School GM fan FOREVER


 
crazycoyote 
Forum Newbie
Posts: 21

Reg: 01-10-15
09-21-17 09:27 AM - Post#2708370    
    In response to wreckmech

Thanks I'll give it a try and let you know.



 
LMC Trucks
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

305 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.519 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 12:30 PM
Top