Engine module firmware update

Some really good mechanics in the area have tested for and advised that an Engine Module flash (or EPROM update) is available for my 1997 Riv. The price of the software is $75 plus labor (electrical installation.) It's affordable but what can be expected from new engine code? Will there be any noticeable performance increase? Will it run better on cheap fuel? (the fuel in North Virginia is lousy, unlike in California.) Will the engine idle smoother than it used to?

In short, will I feel or notice any difference?


-Ed

Click Here (http://tis2web.service.gm.com/tis2web)and enter your VIN in the appropriate box to see the reason for the new software updates. :wink:
(http://tis2web.service.gm.com/tis2web)

Some really good mechanics in the area have tested for and advised that an Engine Module flash (or EPROM update) is available for my 1997 Riv. The price of the software is $75 plus labor (electrical installation.)


Wow....our shop never handled it that way, as far as I remember(Buick Dealership).....if you came in with a driveability problem, and an update was available to fix it, we would charge you for diagnosis time, and the time that it took, to hook up our computer to the vehicle, to download the new program, and any other extra programming that might be necessary(like a crank variation relearn)........it was all labor, and I don't recall a charge for the programming......especially since the programming might have been a necessary fix, due to a flaw in the original programming....

It would be better & cheaper to just purchase another PCM that is already programmed to your VIN with all updates included. It takes about 15-min to install. Click Here (http://www.ebay.com/itm/Buick-Riviera-1997-Engine-Computer-PCM-ECM-16227797-Programmed-your-VIN-/310400284852?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item48454c78b4) BTW, I have used this vendor several times & never had a problem.

Click Here (http://tis2web.service.gm.com/tis2web)and enter your VIN in the appropriate box to see the reason for the new software updates. :wink:


I see the following listed:

"Change to correct 3-4 transmission harsh upshift and enhance post 02 sensor diagnostics, Bulletin Number 876520."

I've had hard up-shifts into OD under certain acceleration conditions. If that can be solved, then it's worth updating the code. Why didn't the head mechanic at another shop tell me about this when I had a Trans Flush a couple years ago?


-Ed

What was the date of the software upgrade? Maybe it was after you had the trans serviced, or the head mechanic simply was not aware of the update.

What was the date of the software upgrade? Maybe it was after you had the trans serviced, or the head mechanic simply was not aware of the update.

I'm not sure what the codes mean, and there's no dates given. The info is: ID=238, Part Number= 9365124, Cal.ID#=9365091, CVN=N/A.

It's referring to Controller: PCM/VCM Powertrain/Vehicle Control Module

But that doesn't sound like an ECM, however there are other engine part numbers for "Control Module Cal History."

- Fix for trouble code P0121
- New Cal for improved speedometer accuracy
- Control Module calibration


The above three plus the trans shift fix. So it's confusing.


-Ed


p.s. can the ECM "learn?" meaning if you drive around town, does it normalize to that type of driving? Conversely if driving 1,000's of miles across the country, will it "learn" highway type driving? Not sure where I got this idea.

How would we know if the calibration has been performed?

How would we know if the calibration has been performed?

The tech said there's an update available for the ECM but didn't provide any version number or information about it. However I was standing there in the shop where they had a PC on the bench in front of the garage bay pulling-up database webpages. This was while the tilt-wheel was apart and they were machining new pins.

I'm pinging the group on what to expect from an engine firmware update. Should go over there today and ask them. The vehicle is back in the shop today for a minor "revisit" on the title wheel.

For that matter, he could have pulled up this discussion thread in front of the car with hood open!! :smokin:

-Ed

Some really good mechanics in the area have tested for and advised that an Engine Module flash (or EPROM update) is available for my 1997 Riv. The price of the software is $75 plus labor (electrical installation.)

Wow....our shop never handled it that way, as far as I remember(Buick Dealership).....if you came in with a driveability problem, and an update was available to fix it, we would charge you for diagnosis time, and the time that it took, to hook up our computer to the vehicle, to download the new program, and any other extra programming that might be necessary(like a crank variation relearn)........it was all labor, and I don't recall a charge for the programming......especially since the programming might have been a necessary fix, due to a flaw in the original programming....

I asked Mike at Chandler yesterday about the "update" and they don't simply plug in a "reflashed PCM" but actually burn the firmware into the controller with a cable. I'm unaware of any updates (no mention by any shop, or never appeared on an invoice) in the entire 15+ years of owning the vehicle, and have to conclude the firmware is pretty much stock, or a very early version.

If the update will improve/correct the 3-4 upshift (which is rough under certain acceleration conditions) then it would be worth it. There's also a TPS engine code mentioned: http://www.obd-codes.com/p0121

I'd like to see a more comprehensive software revision table and will find our what the current installed revision is.

Question: are we talking about the ECM (engine) or PCM (?) One is the engine module and the other is Powertrain? Which does this update apply to? Is that box locted on the firewall opposite the driver near the fender?

-Ed

A little terminology here.....

Basically, the ECM and PCM are the same thing....engine control module vs powertrain control module......

The ECM was used before OBD II......it basically just controlled the engine......when OBD II came along and then the transmissions were controlled electronically, instead of hydraulically, now the module controlled the engine AND the transmission, and became a PCM.....

Newer vehicles today, now have a module just for the engine, and one for the transmission....they are called ECM's and TCM's....

Old ECM's were not "programmed"....you would just change the PROM to update it.....costly and time consuming......then in the early '90s EEPROMs were used.....you would "reflash" the EEPROM....in the beginning, it was done with the Tech I and later Tech II scan tool......now, they hook the car directly to the PC and download new programming into the PCM....They do it for other modules in the vehicle too....

Since you went to the dealership, it would have been very easy for them to show you the updates to the PCM on your vehicle......you then click on the updates, and they tell you what the update does to the vehicle.....most updates don't increase performance, per say......they usually fix glitches in programming for various sensor inputs.....

Since you went to the dealership, it would have been very easy for them to show you the updates to the PCM on your vehicle......you then click on the updates, and they tell you what the update does to the vehicle.....most updates don't increase performance, per say......they usually fix glitches in programming for various sensor inputs.....

Was at the local Buick dealer today where they installed updates in Control Module 16231304 for trouble code P0121, Cal for Speedo accuracy and reduced spark timing error, #9365124 correction for harsh 3-4 shift upshift and enhanced post 02 sensor diagnostics.. all for an electrical labor charge of 110 smackers. There was no charge for the software. Seems to be running as good as ever. The trans update was supposed to hold 3rd gear longer before going into OD? and not to 'bang' OD like it used to under acceleration.

The engine started instantly and ran GREAT. Not a single issue to report. :bananasmi

Ha! they said I needed plugs and wires


-Ed

Like previously mentioned, you could have had another PCM programmed with the latest updates and changed it yourself for less money. Anyway, glad to here it is running better.

Like previously mentioned, you could have had another PCM programmed with the latest updates and changed it yourself for less money. Anyway, glad to here it is running better.

Thanks Z,

I looked through the Service Manual, Vol-2 and on page 6-571 is an illustration of the PCM location with two parallel connectors and bracket. Apparently it's mounted under the passenger compartment dashboard ?? There's no text describing where it is, but the diagram shows what looks like the outline of the forward passenger door frame and a bold arrow pointing FORWARD to front of vehicle. For this task I needed someone that knew exactly what they were doing and could verify the correct codes. The other shop wanted over twice as much, charging for the software AND labor.


-Ed

Most OBDII PCM's are located under the hood, not under the dash.

Most OBDII PCM's are located under the hood, not under the dash.

Thanks for the PM's on the side HotZ.


PCM with dual connectors

After searching through the shop manual, I removed the right closeout panel and there she was.. directly behind the glove box.

http://home.comcast.net/~edwinn/PCM_location_II.jpg


You can just about see the blower motor flange in the lower left corner, and I think the Body Module (or AC control module) on the right.


Another photo of the closeout panel removed. It had dirt and organic sh*t on the backside (foam) which I carefully hosed off.. and flushed the dirt/dust from the molded air passages.

http://home.comcast.net/~edwinn/close-out_panel.jpg


That accessory cover has been missing since the day I bought it. The battery is under the back seat in this model.


Can the PCM update be confirmed with an OBD2 code reader?



-Ed

No it can't......

I like the fact they put the PCM in the passenger compartment of the Riviera. There's less chance of moisture getting in there. If the Riviera had come with a bench seat in a 4-door model, I'd probably want one. But then, a bench and 4 doors would probably go against the Riviera philosophy.

I removed my PCM to inspect the EVAP vent. What a pain getting that thing back together. On mine, there is a weather seal that is really fussy to reinstall, a sight cover that never fits right. It took more time to re and re the PCM than to inspect the EVAP vent. Enjoy your Riviera!

Most OBDII PCM's are located under the hood, not under the dash.

Not on the Riv. As the pix above show, the PCM is under the dash, if you have to R&R it you can take out the glovebox and the passenger side lower dash trim panel...

Bu the way - there is an ignition control module (under the coil pack) and the ABS module (on the firewall) under the hood. There is a body control module under the seat and a module that interfaces with the wireless remote key fob under the rear package shelf.

Not on the Riv. As the pix above show, the PCM is under the dash, if you have to R&R it you can take out the glovebox and the passenger side lower dash trim panel...

Bu the way - there is an ignition control module (under the coil pack) and the ABS module (on the firewall) under the hood. There is a body control module under the seat and a module that interfaces with the wireless remote key fob under the rear package shelf.
Thanks Al,

Had the Riv out today with 132,200+ mile. Weather had warmed-up to 60°F.. and drove it 70 miles in the morning and mid afternoon, mostly expressway. It's been in the garage all winter, except for a few short trips here and there. Runs GREAT!! no complaints.

Except.. there WAS an instance today when I got a "bump" going into OD. It wasn't a "clunk" but a semi-hard shift.. and that was going in overdrive during acceleration. Suppose it can't be velvety-smooth all the time.

The PCM update was suppose to correct the hard shift into OD..

-Ed

Thanks Al,

Had the Riv out today with 132,200+ mile. Weather had warmed-up to 60°F.. and drove it 70 miles in the morning and mid afternoon, mostly expressway. It's been in the garage all winter, except for a few short trips here and there. Runs GREAT!! no complaints.

Except.. there WAS an instance today when I got a "bump" going into OD. It wasn't a "clunk" but a semi-hard shift.. and that was going in overdrive during acceleration. Suppose it can't be velvety-smooth all the time.

The PCM update was suppose to correct the hard shift into OD..

-Ed

Double check fluid condition, you might want to drain the trans, change the filter and fill with dexron VI.

Double check fluid condition, you might want to drain the trans, change the filter and fill with dexron VI.

I had the fluid "exchanged" (it was a BG type machine) in May 2010 and the trans "bucked" and ran pretty rough after that, but settled down after a few weeks. Cannot recall if the OD "bump" started then. I think it DID start after the fluid change.

I'm starting to not believe in service shops anymore and must deal with them in very technical terms.. and with shop manuals as backup. You advise to drop the pan, change filter and refill with Dextron? I know of a good non-retail type Trans shop (located in an industrial row) to go to.

-Ed

I had the fluid "exchanged" (it was a BG type machine) in May 2010 and the trans "bucked" and ran pretty rough after that, but settled down after a few weeks. Cannot recall if the OD "bump" started then. I think it DID start after the fluid change.

I'm starting to not believe in service shops anymore and must deal with them in very technical terms.. and with shop manuals as backup. You advise to drop the pan, change filter and refill with Dextron? I know of a good non-retail type Trans shop (located in an industrial row) to go to.

-Ed

You would have to elicit from the shop personnel how they did the fluid exchange. I do not know what your shop did.

At the shop (a GM dealer) I go to the fluid exchange is that they drop the pan and inspect first anyway, then do a flush with a filter they keep for flushing, then put in new fluid and filter. I have *never* had a problem with their flush. However they explained that it is time consuming to do it right and frankly they charge a lot.

If a transmission has no mechanical problems it really is enough to drop the pan and change the fluid and filter. Be sure they use a filter kit with an OE type gasket not a cork gasket. At a shop that routinely does the fluid changes you won't have to ask. The other thing however you must ask for is they use DEXRON SIX Fluid. GM no longer maintains the Dexron three spec any more, you just don't want it - it will work but it wont last more than 15 - 20 thou miles of average driving. You also do not want Dexron three with any extra mechanic in a bottle additives. Same problem. Dexron Six is a synthetic base fluid, I have used it for many miles, about 50 thou between changes. The only thing is, once you switch to Dex 6 DO NOT SWITCH BACK. I had a mechanic do that once on my Riv, the fluid cooked and grenades the torque converter (clutch burned up).