How do you test ecm on a 1992 buick century 3.3 and what is the prom

no problem told just hunt. sad no?
other answer is for new car Airbox = air cleaner box.
and is wrong.
3.3L GM V6.
most old cars ECM is in passenger compartment far cooler than near any engine, and back then that was true. (hot ecm have shorted lives)
no it is not at hood air box, 1991,


IT IS PNP. (no programming but has a PROM pack)
ACTUAL 99% SENT IN ARE GOOD. INPUT SENSORS BAD. or output actuators bad or 50 other causes and 20 + tests to find them.

here is the real answer and told at Fixya

The ECM is mounted on the right side of the dash above where the passengers feet would be.
The lower panel will need to be removed to see it.
Here is the service manual procedure to remove it.

1. Turn ignition to "OFF".
2. Disconnect battery ground cable.!!!!!!!!!
3. Remove right hand hush panel.
4. Disconnect connectors from the ECM
5. Remove ECM mounting hardware.
6. Remove ECM from the passenger compartment.
7. Remove ECM access cover.
8. Transfer PROM unit to replacement ECM. Using two fingers, push both retaining clips back away from the PROM. At the same time, grasp it at both ends and lift it up out of the socket. Do not remove the cover of the PROM. Use of unapproved PROM removal methods may cause damage to the PROM or socket.

all this is in the service manual, BUY ONE?

this post is for only 1 engine, or for only one VIN
I can not read your vin
or buy the shop manual and read it
real ones are here, or on CD
buy it? and not work blind again. or mess up easy guessing procedures.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=1991+Buick+Century+service+manuals&_sacat=0



end

Why ? What's the problem first , before you replace a good PCM ! ECM Inputs and Outputs Diagnosis

passenger side Under dash on the side kick pad with 3 connector
To replace it .. unplug battery then remove connector at ECM on old ecm remove two screw and the plate remove both memory and install them in the new ECM....plug 3 connectors and battery cable

hope it help

I doubt the ECM from a C body would work on your Century. I would probably buy a used computer and prom from a car exactly like yours. The prom is calibrated to the body style, engine, and trans. Each year and model can be different due to emissions standards.

On this website you find fuse box diagram and description for Buick Century (1992)

http://www.carknowledge.info/buick-century-1993-fuse-box-diagram

The Prom (programmable read only memory) is inside the computers (known as the ECM) sheet metal case, there is a small sheet metal cover over it, remove that cover and simply pull it out using the installation and removal fixture that the prom sits on on top of its socket, VERY IMPORTANT! pay attention to the direction the old one came out and install the new Prom the same way, NEVER FORCE THE PROM INTO ITS SOCKET, IT SHOULD PLUG IN WITH LTTLE EFFORT.

its probably goog puter

Hello.

The ECM is mounted on the right side of the dash above where the passengers feet would be.
The lower panel will need to be removed to see it.
Here is the service manual procedure to remove it.

1. Turn ignition to "OFF".
2. Disconnect battery ground cable.
3. Remove right hand hush panel.
4. Disconnect connectors from the ECM
5. Remove ECM mounting hardware.
6. Remove ECM from the passenger compartment.
7. Remove ECM access cover.
8. Transfer PROM unit to replacement ECM. Using two fingers, push both retaining clips back away from the PROM. At the same time, grasp it at both ends and lift it up out of the socket. Do not remove the cover of the PROM. Use of unapproved PROM removal methods may cause damage to the PROM or socket.
9. Remove new ECM from its packaging and check the service number to make sure it is the same as the defective ECM.
10. Remove access cover.

There you are. I hope your repair goes well.

KL

1992 Buick Century 3.3 liter V-6 VIN "N"




1992 Buick Century 2.5 liter L4 VIN "R"



Hope helps (remember rated and comment this).

1992 Buick Century 3.3 liter V-6 VIN "N"



Hope helps (remember rated this).