GM ECM reflash options?

[ChickenLips]

My beater is a 2009 Pontiac torrent. The ECM has been glitchy. So far reseating the connectors has done the trick to get me off the side of the road. After several events it looks like a matter of time before total failure.

RockAuto has refurbs for decent price but I need to send back a core. RA says "local programming required", so it needs a flash. Dealer wants $150 just for a flash. Dealer replacement $580, not sure if that includes a flash.

I went to a local yard and grabbed a few, non worked. So if I have a good one it'll need a flash.

Now my question, is there options for a flash other than the dealer?

[Ponyryd]

We used to be able to “program” a used ecm with our Autel scanner, program is in quotes because we wouldn’t actually program then so much as program the vin so the ecm would communicate with the network of modules and allow operation.
If you’re wondering if the dealer ecm includes programming then that depends who you called for the quote, if you called the parts dept-no, but if you called service and that price is for the module installed, then yes.

[ChickenLips]

I employed my "call a friend" option. Unlike myself, he's a ligit, licensed mechanic. He said all modules must be programmed now and that he used to be able to do it until GM (and all other manufacturers) stopped selling the appropriate software. I called a dealer and got a quote of $150 just for the programming. My friend said a good used one should be reprogrammable. Google said that once they've been programmed for a particular vehicle a ECM cannot be reprogrammed to another vehicle. I think I'll drive over to a dealer and talk directly to a mechanic. I have 6 I grabbed from a local yard. RA has a refurb for $31 with a core charge of $270. If I need a refurb that'll probably be the way I go. Not a fan of the core charge as I'll surely take a hit on mail, and core refund.

I'm tempted to pop one open for a look. I'm capable of a capacitor swap.

There's a reason I prefer older vehicle with less bells and whistles. I've got 3 perfectly good A9L's

[Ponyryd]

I doubt you’ll be able to speak to a tech, they’ll likely refer you to the manager, asst. mgr, or shop foreman, but if you want to try, go right ahead.
Those A9Ls are probably worth near $500 each right about now.
I suppose the first question I should have asked (and the question the dealer will ask) is “what are you trying to fix/why do you think it needs a pcm”?

[ChickenLips]

I doubt you’ll be able to speak to a tech, they’ll likely refer you to the manager, asst. mgr, or shop foreman, but if you want to try, go right ahead.
Those A9Ls are probably worth near $500 each right about now.
I suppose the first question I should have asked (and the question the dealer will ask) is “what are you trying to fix/why do you think it needs a pcm”?

Pretty good evidence on the PCM being the issue. Problem normally happens when the vehicle is cold. Apply any kind of load at 70+km/hr and the tranny starts slipping, tach dies, cruise stops Stabilitrac warning alarms. I pop the hood and reseat the two 30 ECM connectors and everything reverts to normal.

[ZR]

So you unplug / plug back in and all is well?
How you also tried pulling over, shut off for a couple or three minutes, restart and test?

[ZR]

Just a quick search, similar problems have plagued those cars.

[ChickenLips]

Yes to unplug / plug back in and all is well.

No to pull over, shut off and retest.

Now that I think about it though when the problem happened the first time I limped home and it sat for more than 3 minutes while I did my initial troubleshooting. It was only the unplug and replug that gave me temporary relief. I've gotten pretty spry with this and can do the replug in about 2 minutes. I know this is going to strand me and am loathe to spend any more than the minimum on repairs to my beater. Now that I self assess, I'm loathe to spend more than the minimum on most things other than Mustang parts.

[ZR]

To be sure it's the puter vs a connection, next time it quits, pull cable off the battery n give it a minute or two then back on to test.

[ZR]

I assume you've already cleaned all engine / body ground connections (at both ends of all)?

[ChickenLips]

To be sure it's the puter vs a connection, next time it quits, pull cable off the battery n give it a minute or two then back on to test.

I'll give that a try, and no I haven't cleaned up the grounds, doh. I'll do that too. Now to figure out where they are. Gonna put this job on hold until the snow stops and deal with that first, then try to make room in my unheated garage.

Thanks for the suggestions.

[Ponyryd]

Or better yet, get yourself a code reader or have it scanned and see what comes up…unplugging the pcm is basically just a hard reset, you’re clearing the codes, which sometimes is enough to get it back running fine.
You could also try tapping on the pcm with a screwdriver handle and check for a change in running.

[ChickenLips]

I've got an ODB2 scanner and get the occasional knock sensor code but nothing beyond that. I will try the tapping on the ECM suggestion. Brings back memories of the old B&W TV set. I actually remember going to a hardware store with my father to use the tube tester with a sack full of tubes from the tv. I think I watched the moon landing on that beast.

I must have "reset" the ECM 8-10 times now by the unplug, replug method. Pretty strong indicator (to me) that it's not long for this world and no amount of caressing or tapping is going to get back in the mood.

[Ponyryd]

I’m not trying to sway you, if you’re set on getting a pcm go right ahead, it’s entirely possible that’s the core issue. I remember my old Regal wouldn’t start one day and I was late for work, it was held in with a plastic clip or something so I pulled it out (plugged in still), banged it on the fender and tried it, started right up and worked until I got a replacement.

[redo75]

If you have "reset" the ECM 8~10 times and the car runs for a short time, but the car dies.
Could the issue be somewhere down stream in some component that is sending bad signals to the ECM.
Just a thought to check as ZR said of possible bad grounds, etc. further down stream signal, could be a time consuming troubleshoot, but cheaper than replacing ECM and remarrying it to the car.
Not a mechanic but I stayed in at an Holiday Day in 1980.

[ChickenLips]

Yes I have yet to go over the grounds which I'll do first. I'm just taking a break from snow clearing. Having older neighbors and a big ass snow blower makes you as popular as a guy with a pick up truck on moving day.

I'm not going to spend a nickel until I've exhausted options, so yes to grounds and love taps first.

How the problem presents every time is:
cold start
slow gentle drive for a couple of km's to warm up.
As soon as I hit a ramp or hill prior to vehicle fully warm, the tach drops out, warning lights and tranny starts slipping if in a lower gear
A couple of times this happened just as I was merging onto the highway and in top gear. No problem making it to the next exit, pull off and pop the hood.
I pull the ECM plugs, reseat them and everything back to normal. The brief drive is enough to get the engine up to temperature and no more issues. I've never had the issue when warmed up. It's never cut out any time other than within a couple of minutes of cold start. The leads me to think it could be a bad ground and thermal expansion is just enough to improve the ground.

Anyway, being covid unemployed, fuel prices and laziness makes me disinclined to drive unless absolutely necessary so waiting a few days until warmer conditions is totally doable. It'll take me a half day of shop tetris just to make enough room to get it inside.

Thanks for all the replies. Although obvious, I probably would have overlooked grounds and would not have thought of a drum solo on the case.

[ChickenLips]

this is turning into an epic for this backyard punter.

I cleaned up a number of grounds and went for a test drive yesterday. This time I brought my scan tool. I fired it up cold and induced a failure by putting my foot into it, this time on an uncrowded stretch of road.

I got all the bells and alarms as soon as I gave it some load. This time before unplug/replug of the ECM I plugged in the scan tool and pulled a crank sensor code. No joy at the dealer, Carquest had one. 3 degrees outside so I got to it. Parts department lied on sensor location, call a friend with Mitchels also lied but I only discovered that after pulling a sensor off the bell housing that was out of sight, shoulder deep from underneath. No idea what 2 pin magnetic type sensor that is but it'll be easier to pull next time.

I finally found the sensor on the firewall side of the block located in a spot I could only see with one eye and was conveniently placed tight to a half shaft and adjacent to another sensor that needed disconnecting to even be able to get a thin wall 10mm onto a corroded stud. A couple of brittle connectors, a few eyefuls of rust and a weeks worth of foul language later I pried and cajoled the old sensor out.

I popped in the new sensor and fired up to a Christmas tree of bells, lights and alarms. Turns out with a sensor swap the ECM needs to "relearn" the new sensor. How a dumb magnetic probe needs introductions like a Mormon girl's arranged marriage is beyond me. Then again many things are beyond me.

In any case the sun went down, temps dropped so I buttoned up for a bachelor dinner and some more Netfix riddled with social messaging.

Today it's -10 in the sun and she won't start. I have a can of "Liquid Fire" quick start that didn't live up to it's name. While inside thawing from the 2nd knuckle on all 10 digits i looked up my scan tool. Only the latest models have the "Relearn" function. Mine is 15 years old.

Looks like I have to swap the old sensor back in and hope she'll run. My buddy says he can probably do the program but that means I'll have to drive up there on the old sensor, swap to new at his shop and then program.

I'm warming up now and researching carburetors.

[ChickenLips]

Redo had the right idea. turns out the issue is with the crank sensor circuit. Thanks for prompting me to consider this instead of chasing my first idea of ECM bad.

The replacement sensor needs a relearn. I temporarily put the old sensor in, got a CEL, cleared it and was unable to induce the fault.

My buddy's scanner has the relearn function so I'm heading there to swap in the new and relearn. Hopefully it's just the sensor and not a gremlin elsewhere in the circuit. I am getting to be a pro at swapping the sensor.

[mavrrrick]

let us know please.

[ChickenLips]

It appears that my issues are EGR related, believe it or not.

I visited my friend who generously ran the crank sensor through the learn process. I swapped the old sensor for the new one in under 10 minutes once on the hoist. Another 10 minutes to reprogram and all appeared good, briefly.

I met my friend when he had a speed shop, prior to his divorce. We hit it off and have been friends ever since. Now he's a top notch diagnostics guy in a local garage, and part time race car enthusiast. After shooting the breeze for a long over due catch up session he mentioned his experiences with GM products similar to mine and the LNJ engine I have.

He's seen ECM issues. I explained my unplug/replug temporary solution. and he offered these trouble shooting tips. Remove the ECM and bring inside to warm up for a few hours. Re install and try. If problems resolve it could indicate a board crack or weak solder that is affected by heat expansion and cold temperature contraction. To confirm, remove ECM and put in the freezer to see if problem re-occurs.

He also mentioned he's seem multiple occasions where the EGR has been the source of grief. He volunteered this before I had the chance to mention I've come across similar info online. Between all the sensors and how they share some power and grounds the EGR can cause low voltage sensor signals to get nibble into the border of flakey signal territory and cause intermittent failures.

I hung around for a few hours of shooting the shit and helped change a Ram waterpump. Nice to catch up with old friends and bitch about failure prone chips and sensors needing to be on everything including your toaster and coffee maker.

On my way home I made it about 10km before I got alarms and chimes to "service traction control". This time I had my reader and pulled an EGR code.

I made it home, poured a drink and invited my girl over for some stress relief. This morning I fired up the car and the alarms remained. I immediately shot off so as to remain cold. I did the ECM plug routine to see if I could start the ECM hot/cold test. I went for a 10km drive and no alarms came up.

I ordered a EGR valve from RockAuto.

This is a longish thread not so much on my particular problem but more valuable in troubleshooting. Input here and from my friend has prevented me from wasting money on an ECM non issue (assuming the EGR is the problem).

I will report back when EGR gets swapped out.

[ChickenLips]

So I changed the EGR valve and have been driving for a few days. In this example it looks like a case of; if you’ve got cold feet, put on a hat.

I believe what first looked like an ECM problem, then a crank sensor and now the EGR valve was really a tale of intermingled sensors. I have a real disdain for all of this complexity that introduces more points of failures for some small incremental gains. I can only suppose this is for fuel efficiency and to reduce “carbon footprint”. When I consider all of the time, effort, parts, testing that went into diagnosing and fixing I wonder if the carbon footprint of fixing these gremlins brings the whole endeavor to a net zero and really has the effect of causing retirement of vehicles early simply due to excessive maintenance costs. If I had to pay someone else to do this I could see the bill well north of $500 and making a less stubborn owner look to scrap the beast. Melting down a decade old, sensor laden “smart” vehicle with gremlins to make a 1% more efficient new vehicle is good. Driving a simple, dumb, older less efficient vehicle for 20 years is bad.

In any case I use a RockAuto, Delphi EGR. It was relatively cheap, and arrived quickly. The valve inlet is via tube that inserts into the valve with a single flange bolt. There was a minor misalignment between the bolt hole and tube hole. This turned another 15 minute job into a couple of hours.

I managed to get it on but was dangerously close to snapping the bolt off. So on and off a couple of times, tapping thread, chasing threads and a bit of mallet persuasion got it mounted. I now have an ever so slight exhaust leak that I’ll need to address before the exhaust cuts a channel in the valve, flange, or overly expensive gasket. Since Covid has rendered me unemployed and inflation has escalated operating costs I’m not going far, or often although a trip to Ottawa has been on my mind.

Anyway I’ll delay dealing with the leak and have reserved my Reynaud prone, numb fingers for changing the auger belt on my snowblower, 4 times. Aftermarket replacement belt “it’s not OEM, but will fit”. Which it didn’t but I wrestled on long enough to plow out my 72 year old neighbor and myself before the “will fit “ belt burned up. The multiple trips to repair shop to get the “will fit” belt, return the “didn’t fit” belt and go back for the replacement belt served as my test drive opportunities for the EGR valve.

[ZR]

Good to hear you have it sorted, no it should not be that hard but is what it is.