p0605 after ECU flash

[erikv11]

Earlier this week I reflashed the ECU in my 95, while doing some other repairs. No tuning at all, just a generic flash:

607rev5b, disable all diagnostics except "diagnostics replacement value: intake air temperature" , set all rear cat checks to zero, AC modification.

So now every second or third time I start the car, it throws a p0605 within minutes. That's a TCM code "Powertrain Control Module Read Only Memory (ROM) Error."  Transmission is not doing anything unusual at all, if I clear the code the CEL stays off until the next 2nd or 3rd time I start the car. I already tried re-seating the TCM and ECU.

Here are the other repairs I did: installed Snabb intake, full PCV, put in freshly serviced white injectors (was still on oranges before this), full timing belt job (no water pump). Timing is spot on. 

So I can reflash the ECU, check the ECU pins, re-inspect everything again, but wondered if anyone has any nuggets on this code before I start pulling my hair out?

I have a spare TCM from a 96, but not sure that can swap in to my 95 but it seems unlikely the TCM is actually the problem. 

EDIT: this can be moved to maintenance, I meant to put it over there.

[gdog]

Since you're flashing the ecu, doubt this would get you any answers in the maintenance  section..

Your h/w mods didn't really require an ecu reflash, I'd try a stock ecu to see if that gets rid of the code.   The injector trims will be slightly off but not enough that it wouldn't run fine.

You do have Simply's cksum tool installed, yes?

[erikv11]

Flashing yes, but hardly for performance ... I reflashed the ECU because I swapped in some cleaned and tested injectors, and they happen to be whites. Flash not required, but of course why not reset the injector constant and voltage table from the adjustments I made for oranges. Anyway I flashed it, can't go back!

I do have a few ECUs I can swap in and observe, the V70 will be in town this weekend so 4.4 and 4.3 both, I will try that if a reflash doesn't solve it. Flashing has always been so trouble free, it actually seems more likely related to something getting bumped during the other work, than to the ECU. Fortunately the ECU is an easy test.

Yes on the checksum tool. 

[erikv11]

So here's an update, not solved yet but the problem seems tied to flashing: 

(1) The p0605 moved with the flashed ECU when I swapped the ECU into my 98. Says the flashed ECU is bad, not the 95 car. 

(2) a spare, stock 98 ECU put into my 95 did not throw the p0605. Throws about 6 other codes due to non-matching sensors etc but no p0605. Also says the flashed ECU is bad, not the 95 car. 

(3) I re-flashed the ECU, put it in my 95, same problem p0605. So I figured the flashed ECU somehow had a fluke corruption, hardware problem maybe?

(4) , so I flashed my spare 98 ECU, drop it into the 95,  same problem p0605.

This all together suggests my flashing setup is making bad ECUs that throw the p0605, don't know if the problem is software or cooking hardware somehow. Maybe it's software, maybe my 607 bin is somehow bad, so next I will try downloading a fresh 607 bin, flash it to one of the ECUs, see what happens. 

I have carefully inspected my bench flashing setup, it consists of an ECU harness cut out of a car, wired up with USB cord and banana plugs to a bench top power supply. It looks just fine to me. The flashing goes completely smoothly.

Any thoughts, anyone know how/why this code would be associated with flashing? Very little by a google search except someone had this after an IPD flash. No resolution was posted. 

[erikv11]

So I carefully inspected my flashing rig, all connections look good. I reinstalled TunerPro and all other software, flashed the ECU, same p0605 problem. Pretty consistently every second time I start the car.

Any ideas? 

[gdog]

So you've successfully reflashed an M4.4 ecu for your '95 before this problem started I take it, yes?  Has anything else changed?  New PC, new OS, etc?  Tried a different PC, different cable, etc.?

You could PM me a link to your bin and I could take a look if you want?  What'd be interesting if I take your bin, load it into TP, not change anything, run the cksum tool, and give it back to you.

Actually the more I think about it, wondering if your flashing setup is marginal somehow?  You're bench flashing, right?  Did you try turning up the supply voltage some?  I use 16v; less and I get flashing errs.

[erikv11]

Bench flashing yes, and I am using 14.8v, it's what I have always used. Nothing changed on the setup - same old PC, OS, cable.  Successfully flashed maybe 15 times I would say, between reflashes for my two turbo vehicles plus for a couple other people. I'll send you a link to the bin when I get back to that PC. 

I will definitely give it a try at 16v, thank you.

[erikv11]

Well, flashing at 16v didn't change, threw p0605 on third startup. PM sent to gdog.

[erikv11]

I've got a working flash now from gdog (thank you!), he took my file and checksummed it, when I got it back at first it wouldn't flash then it would ... (I know, huh?).  Anyway I started the car six times today and no p0605 so I think I am out of the woods for the time being.

But I don't really know what is up with my flashing setup. It appears his idea about a checksum problem is probably correct. In the TunerPro-RT directory, my setup has both the stock TPChecksumPlugin.dll and sImply's TunerPro Motronic 4.4 CheckSum.dll  am I supposed to have them both in there? 

[erikv11]

So my flashing setup now detects a checksum error and fails, with files that previously it would flash. It can also repair those errors by hitting save, and the files then flash fine and work with no CEL. So I don't know what the problem was with my rig, but it was related to the checksum and it's fixed now.

One thing for sure, the p0605 came from flashing a file that wasn't checksummed properly.