E38 GM SPS Programming

[CRTD]

Hello all. Trying to use GM Techline SPS and MDI to flash a stock cal to a used e38 ECM with same service number (12612384). This is for a 2008 Tahoe 5.3 VIN 0.

So far have been unsuccessful. First attempt was with one from an Impala V6 car. Same service number. GM SPS detects a different VCI and asks if I want to Accept, Overwrite or Cancel. I am able to flash the replacement ECM with the correct calibrations and VIN, learn the VTD. But it starts poorly and runs lean. Barely performs the CKPV and sets DTC's for AFM solenoids.

Read some info about TAC throttle info not being update-able in the ECM and causing trouble.

So tried an ECM from a 2008 V8 truck and does the same thing.

Is there a remedy to this? Or should I just buy a new ECM?

Thank you in advance.

[blindsquirrel]

HP Tuners only reads/writes 6 of the 8 segments, GM SPS writes all of them.

What are the full VINs of the calibrations you're trying to flash into it/them?

[CRTD]

1gnfk13058r115522

[edcmat-l1]

Hello all. Trying to use GM Techline SPS and MDI to flash a stock cal to a used e38 ECM with same service number (12612384). This is for a 2008 Tahoe 5.3 VIN 0.

So far have been unsuccessful.

^^^ First you say it's been unsuccessful.

First attempt was with one from an Impala V6 car. Same service number. GM SPS detects a different VCI and asks if I want to Accept, Overwrite or Cancel. I am able to flash the replacement ECM with the correct calibrations and VIN, learn the VTD. But it starts poorly and runs lean. Barely performs the CKPV and sets DTC's for AFM solenoids.

Read some info about TAC throttle info not being update-able in the ECM and causing trouble.

So tried an ECM from a 2008 V8 truck and does the same thing.

Is there a remedy to this? Or should I just buy a new ECM?

Thank you in advance.

But then you say you were able to flash the VIN, etc.

So, either you were able to successfully flash it with SPS or you weren't. The fact that it doesn't run right after the flash is immaterial. SPS is only going to flash a GM update. It's not going to wipe out AFM codes if you've done an AFM delete. It's not able to modify anything, only write what the GM server uploads.

So let's back up and talk about what you're trying to do, what's been done to the vehicle, etc.

[CRTD]

Nothing done to vehicle. It has a bad ECM. Trying to replace it with a used one. Bone stock. The original complaint is the EVAP vent solenoid ckt. It is stuck on all the time by a failed driver in the ECM or some other issue.

Anyway, that is the reason for the replacement. With the original ECM in the vehicle it runs fine. I have even gone so far as to update that ECM and it runs fine on the same cal I am trying to put into the used e38.

The issue I am trying to fix is the SPS programming of the used e38 ECM. Perhaps I am breaking some rules I am not aware of or, it just isn't possible. But it seems unlikely that's the case.

[blindsquirrel]

The last bad ECM I saw in a GM looked like this...

dang_ol_brain_box_done_gone_bad_agin.jpg

[edcmat-l1]

The last bad ECM I saw in a GM looked like this...

dang_ol_brain_box_done_gone_bad_agin.jpg

Yeah pretty much same here. I translate "Bad PCM" to "I don't know what I'm doing".

No offense OP, it's just incredibly rare for GEN4 PCMs to go "bad". Don't know when the last time I've seen one.

PS back in the day, we used to call the tin box ECUs "flash cubes" LOL A lot of guys here are probably too young to know what one of those is LOL

[CRTD]

Yeah that's real funny guys. Very helpful too. There is no question on the diagnosis. So put that to rest please.

Have either of you used GM Techline SPS to program a used e38 recently? Have something of value to add as it relates to what can, or cannot be done? Or if something may have changed on GM's end? That would be appreciated.

[edcmat-l1]

Yeah that's real funny guys. Very helpful too. There is no question on the diagnosis. So put that to rest please.

Have either of you used GM Techline SPS to program a used e38 recently? Have something of value to add as it relates to what can, or cannot be done? That would be appreciated.

I own an MDI2. I've owned a TECH1 way back when, then a TECH2, skipped the MDI and went right to the MDI2.

I'm a former GM tech. I use SPS weekly.

What's "bad" about the PCM? What failed in it?

When you put a used PCM in a vehicle, it will identify that VIN. IN SPS you choose "Replace and reprogram" you override the VIN in the PCM and enter the VIN you want programmed to it.

I can do it Monday and take screen shots and post them here if you want me to. I'm gone for the weekend.

Still want to know what's bad about the old PCM. If it's bad I'll take it from you. I'll send you a shipping label.

[blindsquirrel]

We're not trying to be funny, we're just two guys that have combined between us something like, what is it, 45, 48 years in GM dealerships?

[Alvin]

I've had a handful of bad ECM's. Processor codes.


I've also had them do wierd things like the IAT going to some odd ball number only at WOT. I would have thought it would be a wiring issue but a new computer completely fixed it.

[edcmat-l1]

30 years now as a certified master tech. About 6 years in a GM store in the 90s. I was an AC Delco shop for quite a while so benefitted from the same training for several years after.

[edcmat-l1]

I've had a handful of bad ECM's. Processor codes.


I've also had them do wierd things like the IAT going to some odd ball number only at WOT. I would have thought it would be a wiring issue but a new computer completely fixed it.

I can't remember the last GEN4 I had that needed a PCM replacement to fix something. I can think of a small handful of GEN3s I've replaced to fix oddball shit. But even on those it's hard to know if it's the box (unless it's an obvious driver problem) or the new fresh flash that fixes it.

[CRTD]

Yes, I understand this. So when going thru the replace and program procedure, with a used ecm, I get a popup from GM. States a new VCI is detected and offers 3 choices. Accept, overwrite, or cancel. Whether I accept or overwrite I get the same end result. It accepts the VIN, the calibrations and the VTD learn. But it runs terrible. And the main issue we are trying to fix, the Vent solenoid ckt being stuck on in the ecm, is gone. I can output control the vent solenoid now like normal. However, it runs terrible, O2 data is very low, Fuel trim doesn't correct. Sets AFM solenoid DTC's it never did before. Etc.

[blindsquirrel]

Oh, well we're well over 50 years then, I think I was at 22 when I finally gave up.

[blindsquirrel]

Let it gather info (the old VIN) from the old ECM, instead of inputting it yourself. It should walk you through the steps, tell you when it's OK to turn things off and swap ECMs, etc. Or at least it used to, assume it's still the same.

Did you get the VIN you're trying to program with off the truck, or as read out from the original ECM?

[verlon]

I can't remember the last GEN4 I had that needed a PCM replacement to fix something.

I have a pack of them.
2 E38 and 1 E67A with one dead knock sensor channel
3 E38 with dead 5V reference #1 (caused by faulty AC Pressure and/or Fuel Tank Pressure sensors with excessive current drain but not enough to trigger overcurrent protection and 5V regulator is simply overheated)

[CRTD]

Went thru it again with the used truck ECM. The donor vehicle was a VIN J 5.3 and 2WD if that turns out to have any bearing on this.

This time it does not give pop up about new VCI like before. It has the same calibration I am trying to program in it already (from the first time). A pop up warns me of this. Reprogrammed it again anyway. Relearned the VTD again. Same result. The Vent solenoid issue is gone/fixed. But it runs awful again (it did not have any performance issue with the bad ECM). At this point, I'll just buck up the $300 for a new one. Maybe we can get some answers regarding the programming of a used one still.

[blindsquirrel]

Whatever is happening is not caused by the act of reprogramming a used ECM with SPS.

Did the VIN you're programming it with come out of the old ECM, or off the VIN tag or door sticker?

[edcmat-l1]

Went thru it again with the used truck ECM. The donor vehicle was a VIN J 5.3 and 2WD if that turns out to have any bearing on this.

This time it does not give pop up about new VCI like before. It has the same calibration I am trying to program in it already (from the first time). A pop up warns me of this. Reprogrammed it again anyway. Relearned the VTD again. Same result. The Vent solenoid issue is gone/fixed. But it runs awful again (it did not have any performance issue with the bad ECM). At this point, I'll just buck up the $300 for a new one. Maybe we can get some answers regarding the programming of a used one still.

What is wrong with the "bad" PCM?