Replacing computer

Hey, does anyone know what I need to do about replacing the PCM (brain, computer) on my Montana. It is a 2000 and it keeps setting DTC 1810. We have replaced and checked everything that the book is saying to do. The last thing is that the PCM needs to be replaced.

I have contacted the dealer and they say that it needs to be replaced or "reflashed" and that they cannot do it at the dealership but that they need "to send it in to GM and have them do it."

Can I get a used one and just replace the thing myself. AllData.com says that I need to

"REMOVAL PROCEDURE

Disconnect the negative battery cable.
Remove the coolant reservoir retaining bolt.
Remove the coolant reservoir and set aside.
Remove the SMCC module from the SMCC module bracket.
Remove the SMCC module bracket.
Remove the 3 bolts from the strut brace.
Remove the left front strut brace.
Unsnap the PCM cover and remove the PCM cover from the air cleaner housing.
Remove the PCM from the air cleaner housing.
Disconnect the PCM electrical connectors.

INSTALLATION PROCEDURE

Connect the PCM electrical connectors to the PCM.
Install the PCM into the air cleaner housing.
Reinstall the PCM cover to the air cleaner housing and snap the retainer.
Reinstall the left front strut brace. NOTE: Refer to Fastener Notice in Service Precautions.
Reinstall the 3 strut brace retaining bolts.
Reinstall the SMCC module bracket.
Reinstall the SMCC module to the SMCC module bracket.
Reinstall the coolant reservoir. Be sure to check coolant system for proper level.
Reconnect the negative battery cable.
If a new PCM is being installed, program the EEPROM.
The PCM will need to learn the crankshaft variation. Refer to CKP System Variation Learn Procedure ."

With getting an old one do I need to have the PCM learn the crankshaft variation?

Sorry that this is long but felt that I needed to include all of this.

You certainly can do the job yourself. You will be better off finding one that fits your particular model and engine combination. Once you replace the PCM you will need to do the Learn Procedure so that it can properly read the sensors. It really is not that hard a job to replace and will save you some major bucks by doing it yourself. Good Luck and post again when you get it completed to let us know how it turned out.

:banghead: :uhoh:

Hey, I put in the computer that I picked up (used) and tried to start the van and nothing happened. I hooked everything back up properly and such and nothing. I am at a loss.

What does it entail in "learning" the computer. I do not have any scan tools or anything so what am I going to have to do? I am at a loss. I am about ready to just trade the piece off. Help.

Thanks for any suggestions.

Joe in Kansas City

Joe, To do the learn procedure the van must run. It is possible the used computer you purchased is either the wrong one or is bad. Take it back to the place you bought it and tell them what happened. They should give you another one without any hassle. Also make sure all your grounds are connected especially the one for the ECM as this will prevent it functioning properly.

Please keep us posted!

I may be wrong, but I thought that you had to enter the vehicles VIN number in the replacement PCM and do other things that require a scan tool.

I may be wrong, but I thought that you had to enter the vehicles VIN number in the replacement PCM and do other things that require a scan tool.

Don't know about this but it sounds feasible...however, consider....

"If a new PCM is being installed, program the EEPROM*"

* EEPROM or double E PROM is similar to flash memory (sometimes called flash EEPROM).

I may be off base here, but I think that programming the PROM (that can't be done in the dealer's shop?) refers to a little known fact about production automobiles.

Manufacturers use RPO's (regular production options) to define the content of a given batch of vehicles. (Applies more to medium and heavy trucks where each truck is quite different based on its designed purpose, but the principle is the same).

What this can mean is that depending on the sequence of a build cycle and where a particular vehicle is in that cycle on the assembly line, different sensors or other connected devices are used on a vehicle based on availability (multiple suppliers?).

We're talking generally about electronics here and each component although it may have the same purpose (ie MAP sensor for instance) may have different electrical characteristics (depending on the supplier) that the computer needs to be able to recognize.

This is primarily the reason for the PROM or flash write to memory so that a specific vehicle's RPO can be programmed in and the 'learning process' completed. The VIN may contain some of, or all the necessary RPO information.

This may not have anything to do with why the van won't run, but an experienced tech may clarify and even allude to some of the info above.

.

I took the used computer back. The parts store was not real helpful in getting another one. I went to my local mechanic and he said that it does need to be flashed and that I should really go to the dealer to do that. I am thinking about biting the bullet and talking with my local dealer and seeing what he says. We have moved to south central kansas and he is in Great Bend. I will let you all know what he says.

I am thinking about trading the Piece off if this cannot get figured out. I have about had it with this Ponticrap.