Deville 2000 ECM location and replacement

[Oldgamer]

Hi guys,

that site changed so much after I been here last time!

I hope you well and running.

I will help to replace engine computer module (ECM) in his Deville 2000 tonight.

I did it for my 94' STS in 2001 fine, but I'm not sure about Deville 2000 ECM location and procedure. I remember in my STS it was located under glove box and I pull out chip from old ECM and inserted into new one to have it programmed with old settings. Then I made a "learning" procedure. Is the replacement of ECM in Deville 2000 similar to this?

Thanks guys for any help.

[Ranger]

After OBDII the ECM (Engine Control Module) became the PCM (Powertrain Control Module). It is located under the air filter box for cooling purposes. Removal should be pretty self explanatory I think once you see it.

[Bruce Nunnally]

Ranger's answer is good. Please also see the technical description here which should help with more information on PCM removal and reprogramming.

[Oldgamer]

Ranger's answer is good. Please also see the technical description here which should help with more information on PCM removal and reprogramming.

Thank you very much guys!

I just come back home and found your messages...

Well, after we didn't find PCM behind the glove box we tried to remove air filter box, and you can not beleive it we didn't finish... We remove couple screws wich keeps filter cover, remove filter, but didn't remove whole box, some screws been kinda deep, we need to find longer tool to remove couple of them. I tried to look if I will see at least an edge of a PCM, but didn't see anything, even cables.

Couple more questions:

1. Should we remove rear seat to disconnect the battery, or it can be done easier?

2. In my old OBD I computer I just changed the chip. As I understand from your messages, PCM should be programmed, I can not just change chip here. Should I bring PCM to shop to program it or it can be done through some procedures similar to "Idle learning" or something like that?

Thanks for your support.

I guess I like OBD I more and more and like OBD II less and less...

[Bruce Nunnally]

Yes, you need to disconnect the negative cable at the battery.

The PCM has to be reprogrammed with a Tech II unit, something mostly only the dealers have.

courtesy shop here

Why does the PCM need to be replaced?

[Oldgamer]

Yes, you need to disconnect the negative cable at the battery.

The PCM has to be reprogrammed with a Tech II unit, something mostly only the dealers have.

courtesy shop here

Why does the PCM need to be replaced?

Thanks for asking!

Well, something strange going on with the car.

History: Crankshaft position sensors have been replaced couple years ago (Deville 2000, engine stall, you know that famous defect for Deville 2000). After replacement everything was fine. Couple weeks ago engine start to stall again. Well, we thought that it is again crankshaft sensors, but weren't sure. My friend went to shop and they didn't find any serious, only code P0741 was there, but car had this code (I guess it is a TCC slippage) a long long time and it never leaded to engine stall. Whenever engine stops, it can be started rightaway with no problem. That was very similar to famous crankshaft position sensor and my friend went to mechanic. Mechanic warned him that he thinks that sensors are fine, but my friend still ask to change sensors. Sure enough, after paying $280 problem still was there. I checked codes and didn't find anything serious, it was a bunch of codes in history (ABS C1223, C1224, C1248, C1295, P1540, IRC U1016, IRC U1016, P1106, RIM C0625). I cleared codes. Then we drove a car a bit and sure enough, in 3-4 min engine stall. I checked codes and it was NOTHING there! We start engine with no problem and in 30 sec engine stall again. Sometimes my friend drive 20miles without a problems. Very strange.

I desided to try to change computer because absence of codes, better say, look irrelevant to engine stall (I can not be sure here). I ordered computer very cheap ($40 with shipping included), so why not to try? Too bad I didn't know I can not just replace chip here as I did in my computer.

That is my (better say my friends) story.

Thanks!

[BodybyFisher]

Hey good to see you again! Hope you have been doing fine!

Didn't you once help BLUNTED with his shift solenoids?, Mike (formerly Scotty)

[Bruce Nunnally]

Here is the diagnostic for Stalling:

Rough, Unstable, or Incorrect Idle and Stalling

Checks / Action

DEFINITION: Engine runs unevely at idle. If severe, the engine or vehicle may shake. Engine idle speed may vary in RPM. Either condition may be severe enough to stall the engine.

Preliminary

* Refer to Important Preliminary Checks Before Starting in Symptoms .

* Search for bulletins.

Sensor/System

* Check the PCV system for proper operation.

* Check the throttle body, and TP sensor for proper operation and damage.

* Check the knock system (KS) for excessive spark retard.

* Check the EGR system for proper operation.

* Check the IAC valve and valve housing for deposits and/or damage.

* Check for dirty or damaged air cleaner element.

* Check for collapsed or damage intake air ducting.

Fuel System

* Check the fuel pressure. Refer to Fuel System Pressure Test .

* Check the fuel injectors and related wiring. Refer to the following:

o Fuel Injector Balance Test with Special Tool or Fuel Injector Balance Test with Tech 2 .

o Fuel Injector Coil Test - Engine Coolant Temperature (ECT) Between 10-35 Degrees C (50-95 Degrees F) .

o Fuel Injector Coil Test - Engine Coolant Temperature (ECT) Outside 10-35 Degrees C (50-95 Degrees F) .

* Check the minimum idle speed.

* Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

* Check for items that cause the engine to run rich, or lean.

Ignition System

* Check the IC circuits for proper connections at each ignition module assembly.

* Check for proper ignition voltage output using the spark tester J 26792.

* Check the ignition coils for cracks, or damage.

* Check for a missing or damaged ignition module assembly grounding spring.

* Check for misaligned, or damaged spark plug boots.

* Check the spark plugs for the following conditions:

o

Important

If the spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.

fouling

o cracks

o wear

o improper heat range or reach

o incorrect gap

Engine Mechanical

* Check the following:

o engine compression

o sticking or leaking valves

o worn camshaft lobes

o valve timing

o worn rocker arms

o broken or weak valve springs

o excessive oil in the combustion chamber-leaking valve seals.

* Check for incorrect basic engine parts. Inspect the following:

o camshafts

o cylinder heads

o pistons, etc.

Additional Checks

* Check the exhaust system for possible restrictions.

* Check for fuel loading in the EVAP system.

Also, have you considered the fuel pressure regulator?

[Bruce Nunnally]

I added a tech note on Diagnosing intermittent conditions.

[Oldgamer]

Hey good to see you again! Hope you have been doing fine! Did you buy another Cadillac?

Didn't you once help BLUNTED with his shift solenoids?,

That's right Scotty, I'm back for help, but I didn't buy Cadillac.

I tell you what: after driving Honda Accord V6 I like my STS (I don't have it anymore ) more.

I can not tell you that Hohda is bad, no, it is actually a dissent car for the price and has a lof ot horses under hood for it (I guess it is 268). I think that Northstar is the best engine and I drove my Caddy with a joy. Honda's 5 speed transmission work up and down too often for my taste.

How are you?

I remember you everytime I remember that forum.

I hope you well too.

OK, I guess I should go to bed. (some noise out there :)

Later!

[Oldgamer]

I added a tech note on Diagnosing intermittent conditions.

Thank you so much!

The thing is that idle and actually everything is working fine, I mean, no rugh, stable idle, good start on cold or hot. Very strange. Even more strange no cedes left after engine stall. I think it can be some electrical problem, but it is hard to find. Probably some ground problems? Hmm...

Thanks guys!

[Oldgamer]

Guys,

unfortunately I can not see these images when I click on a posted link how to replace the PCM.

That's why I want to ask other question:

when I looked on a intake air filter assembly it didn't look same as on my STS. I saw big plastic box in place between air filter cover and laft front head lamp closure. I think it is for intake air.

So, I try to understand should that big plastic assembly pulled out with a air filter box, or these two boxes are separate and PCM is placed right under air filter (I didn't see much space there, can not understand how it is enough space there).

Second thing:

programming of PCM is not easy and can not be done without special tool.

We bought used PCM from Deville. I guess you know now what I'm thinking.

I think that is not big deal just try if it will work right away, and probably things like idle and other settings computer will adjust. I don't think that something really bad can happened. Probably engine will not start or idle will be rough or something like that. Anytime we can insert old PCM back.

What do you think?

Thanks!

[Logan]

You cannot reprogram a used PCM from a 2000 Deville.

The PCM and other modules can only be programmed 1 time. The VIN # is part of the programming procedure.

The system will try to program, but it will hang up at about 90%.

GM has a bulletin about programming can only be done 1 time. After that you have to replace with a fresh module.

[Oldgamer]

You cannot reprogram a used PCM from a 2000 Deville.

The PCM and other modules can only be programmed 1 time. The VIN # is part of the programming procedure.

The system will try to program, but it will hang up at about 90%.

GM has a bulletin about programming can only be done 1 time. After that you have to replace with a fresh module.

Thanks for reply,

does it mean that you can not program any used PCM?

Now, again, I like OBD I even more

[Logan]

On the newer cars, you can update the software for that vehicle. But you cannot reprogram it for a different vehicle.

"When a PCM or a body control type module is replaced, the VIN information must be programmed into the replaced (new) control module. A module which has had VIN information entered into it (for example, one taken from another vehicle) cannot be reprogrammed. VIN information can only be entered into new modules. "

[Ranger]

Guys,

unfortunately I can not see these images when I click on a posted link how to replace the PCM.

That's why I want to ask other question:

when I looked on a intake air filter assembly it didn't look same as on my STS. I saw big plastic box in place between air filter cover and laft front head lamp closure. I think it is for intake air.

So, I try to understand should that big plastic assembly pulled out with a air filter box, or these two boxes are separate and PCM is placed right under air filter (I didn't see much space there, can not understand how it is enough space there).

Thanks!

Open the air filter box and remove the filter element. See the intake hole in the bottom? The PCM is right under it so it is cooled by intake air.

[Oldgamer]

On the newer cars, you can update the software for that vehicle. But you cannot reprogram it for a different vehicle.

"When a PCM or a body control type module is replaced, the VIN information must be programmed into the replaced (new) control module. A module which has had VIN information entered into it (for example, one taken from another vehicle) cannot be reprogrammed. VIN information can only be entered into new modules. "

Thanks Logan,

as I understood used PCM can not be used on a vehicle with different VIN number.

It is interesting why I should change VIN number, how PCM knows that it is connected to other vehicle, unless it got info from some other components in a car.

And how come that many used PCM you can find out there for sale.

When I order it salesman told me that it should be programmed, but he didn't tell me it can not work on a other car.

[Logan]

"Class 2 Serial Data Communication allows control modules (i.e. the Powertrain Control Module (PCM), the Body Control Module (BCM), the Dash Integration Module (DIM), the Instrument Panel Cluster (IPC), the radio, the Heating, Ventilation and Air Conditioning (HVAC) Controller, and the Sensing and Diagnostic Module (SDM) to exchange information. This information may be operational information or identification information. Among the identification information exchanged and compared within these modules is the Vehicle Identification Number (VIN)."

Above info from GM bulletin.

I bet car won't even start with the used PCM.

As for PCM's being sold on the internet. www= wild wild west. That's why it was only $40.

I'm not trying to be an *smurf*..

You can try to reprogram it. We know how this will end. Been here before.