Corrupt PCM trims be wild...

[Blue Bee]

So I?m fixing a tune for a ?16 Charger 6.4, has LT?s and a 274 comp cam. Car ran like crap, made about 370hp on initial pull when it came to me and very unsafe. With the number of places it?s been to I?m wondering if it has been loaded with Diablo and HP tunes...as the PCM does wild trims, like -25 on bank 2 and +30 on bank one. I set up two wide bands in the rear ports and sure enough, I can make it run stoich then PCM starts doing those trims, makes one WB read 16.0 and the other 10.0. The trims do not follow the O2?s, I?ve swapped them, changed out for other good ones, the only way I can keep it running good is full open loop so PCM doesnt make any changes. Sound like a PCM is corrupt? I noticed at some point VE was messed with, VVT is disabled so I turned NN off and did full tune with WB error versus commanded in VE tables, have car running great, but then enable CL and PCM screws it all up. I just don?t want to tell customer he really needs a new PCM if it?s something I?m missing.

[lafrad]

are the narrowband sensors all plugged in in the right spots? I've seen plenty of cars where *somehow* a pair of sensors gets swapped left to right or front to back, and the ECU does things like this... maybe pull one bank of O2 sensors (just leave them plugged in but hanging in the air)... if that bank is NOT the one that goes rich... then... ?/??

This would also go for the injectors.... people do crazy things when they have them apart and don't write down/take pictures of how it all goes back together.

[[email protected]]

Rick,
We have had several 16 6.4's show up here with the exact same issue. Tuned elsewhere and the customer was complaining of poor performance and CEL's. When we datalogged we saw the exact same issue as you are seeing. We verified that the O2's were correctly placed then replaced both O2's and the problem continued. These cars were tuned elsewhere using CMR. We returned the vehicle to stock/unmarried the tool, modified the tune with HPtuners and the problem continued. We then reflashed the vehicle with Witech and retuned on HPtuners and the problem was resolved. I'm not sure if this will work for you but it was a 2 out of 2 fix for us.

[Jay@HAP]

Rick,
We have had several 16 6.4's show up here with the exact same issue. Tuned elsewhere and the customer was complaining of poor performance and CEL's. When we datalogged we saw the exact same issue as you are seeing. We verified that the O2's were correctly placed then replaced both O2's and the problem continued. These cars were tuned elsewhere using CMR. We returned the vehicle to stock/unmarried the tool, modified the tune with HPtuners and the problem continued. We then reflashed the vehicle with Witech and retuned on HPtuners and the problem was resolved. I'm not sure if this will work for you but it was a 2 out of 2 fix for us.

Thanks for posting that. I haven't ran into that yet....

[Blue Bee]

Thanks guys, yes I double checked O2 plug in placement, rears are disabled and swapped O2’s and all that making sure that was not the issue. I think multiple Tuners is the problem here as well, the customer bought the car (3 months ago out of state) and probably didn’t get the Diablo box is what I’m thinking, and a local shop here messed with it using HP Tuners. So short of replacing the PCM or having Dodge over-flash same number or update flash I don’t really see any other way of getting this straightened out.

[lafrad]

You may be able to call HPT or Diablo and have them help get a "return to dealer spec" calibration written to the ECU.

The dealer's tools should just wipe the whole thing clean and write the latest Calibration to the thing... that would be the cleanest/quickest option. Just be ready to re-read that new tune and copy all your work into the new file in the parking lot

[Homer]

This is a shot in the dark, but I notice that when increase my enrichment rate values, the fuel trims go ape ship and I eventually get a SES light with DTCs saying all my injectors are in open loop. When it happened I thought I fried the injector drivers but once I put those values back to stock the car behaved normal and the DTCs went away. I thought it strange since I see a lot of tunes with these values increased but for some reason my PCM no-likey.

Oh and the O2 sensors are the original stock ones with only 20k miles on them.

rate.JPG

Ah, I see Mike had seen this problem before on 2 other vehicles. Nevermind.

[mxatunerjg]

Over the past year and a half we have had this problem on quite a few cars. All of them had one thing in common and that is the PCM was unlocked by Diablo and all had been flashed by a Diablo handheld device at some point in their life. We sent a few of them back to Diablo, and recently I had another one that really upset me due to some other circumstances with them. I contacted them and wanted some sort of explanation as to what was going on. They told me they aren't sure what is causing it, but they do know that all they are doing is flashing the PCM with a new cal and sending them back out to other customers. So that got me thinking, there are only 2 things different with what they did vs what we are doing. They are flashing it with a factory tune (which one that we had done we tried this as well without luck)...the other thing that is happening is power is being removed from the PCM for an extended period of time while it was shipped to them. So disconnected the battery on a vehicle that was doing it and let the car sit overnight. Came in the next morning, hooked up the battery, and it worked fine. We tried this again on another vehicle and had the same result.

[Homer]

Could it be that removing power does a better job at completely erasing the adaptives?

[mxatunerjg]

Could it be that removing power does a better job at completely erasing the adaptives?

I'd agree if it weren't for the testing I've done when I've encountered this issue. Except I have cleared adaptives, started the car with a wideband connected. Watched the vehicle o2 sensor data and a wideband both read correct, then as soon as closed loop begins the trims on the left bank only rise to 30% and the wideband go to 10.0 AFR and the vehicle o2 read max rich. Yet the right bank was dead on 0 trim and both the wideband and vehicle sensor for that bank be right on. I've even gone as far as running an extension harness on the left and right primary sensors and physically putting the sensors in the opposite banks. The same result, bank 1 would rise to max trim and bank 2 would stay at or near 0 trim in the computer. This all can happen to a car that has been running and driving for days, then all of the sudden one bank trims wildly rich or lean. I've unhooked the battery and fixed it, and I've replaced PCM's and fixed it, all with no change at all to the tune.

[Homer]

I'd agree if it weren't for the testing I've done when I've encountered this issue. Except I have cleared adaptives, started the car with a wideband connected. Watched the vehicle o2 sensor data and a wideband both read correct, then as soon as closed loop begins the trims on the left bank only rise to 30% and the wideband go to 10.0 AFR and the vehicle o2 read max rich. Yet the right bank was dead on 0 trim and both the wideband and vehicle sensor for that bank be right on. I've even gone as far as running an extension harness on the left and right primary sensors and physically putting the sensors in the opposite banks. The same result, bank 1 would rise to max trim and bank 2 would stay at or near 0 trim in the computer. This all can happen to a car that has been running and driving for days, then all of the sudden one bank trims wildly rich or lean. I've unhooked the battery and fixed it, and I've replaced PCM's and fixed it, all with no change at all to the tune.

Do you get any DTCs when this happens?

[06300CSRT8]

Can one of you guys post a tune and a log of one of these vehicles while it is doing this strange behavior?

[mxatunerjg]

This is not much help as it was just me trying to get a very fast log to see what was going on. The PCM and tune had 4000 miles on it at this point. I had removed all aftermarket components and loaded the factory tune file to the vehicle just prior to this log to try to eliminate things. The only thing that was not stock were the headers. It is the only log I have saved of one of these PCM's doing this. After this log I removed the computer, sent it to Diablo, and got a new one (they know there is an issue but do not know why it is happeneing). I installed aftermarket parts, loaded the same tune file that I had been using for the previous 4000 miles, and have never had an issue since. The customer drove the car for about 8 months with that same setup, then traded it on a Hellcat. Now one of our employees owns the same car with the same setup and it has seen 10000 miles since that issue in August of last year. Same parts, same tune, only thing that changed was the PCM.

fuel test.hpl

[mxatunerjg]

Do you get any DTCs when this happens?

It has been a bit since I've had one do it, but if I remember correctly it gives a lean code for the bank that goes haywire.

[Jay@HAP]

I had a Scat Pack Charger do something similar. Only mods were headers. The car was stock, I had the PCM unlocked by HPT. I found out if I changed the transport delay any it would cause bank 2 to so some weird stuff. This is the only time it's ever happened to me.

[06300CSRT8]

Ah yea Jay I remember having the same issue too, mine was even weirder. On my old 2006 srt8 Chrysler, when I returned the PCM to stock including the transport delay, trims were really wacky and wouldn't settle down. To this day the new owner still has my non stock transport delay tables on his 100% stock car.

Maybe the transport delay is learned but then not reset with the clear adaptives?

[Jay@HAP]

Ah yea Jay I remember having the same issue too, mine was even weirder. On my old 2006 srt8 Chrysler, when I returned the PCM to stock including the transport delay, trims were really wacky and wouldn't settle down. To this day the new owner still has my non stock transport delay tables on his 100% stock car.

Maybe the transport delay is learned but then not reset with the clear adaptives?

Man I don't know. I was to the point I thought there was something wrong with the PCM. It sucked because you would have to drive it for a while to get it to do it. The car came back multiple times for a CEL showing bank 2 was rich. And of course it was "one of those customers" that added to the problem that didn't help.

[mxatunerjg]

I had a Scat Pack Charger do something similar. Only mods were headers. The car was stock, I had the PCM unlocked by HPT. I found out if I changed the transport delay any it would cause bank 2 to so some weird stuff. This is the only time it's ever happened to me.

On all the cars that have done this to me, not one had the transport delay table adjusted. Also, I noticed you said that you had one you would have to drive for a while to get it to happen. All of the cars I've had do this would do it as soon as closed loop began. Just like is shown in the log I posted. I could start the car and it would run perfect...then as soon as closed loop started the fuel trim on only one bank would rise to full positive. The other bank would be normal and the bank that would rise would be running extremely rich (10.0 ish AFR) and black smoke coming out of that bank.

I've never had this happen on an HP Tuners unlocked PCM, and I don't believe I've ever had an issue with a car that had been tuned with ONLY HP Tuners. I think all of them were cars that at some point had been Diablo tuned.

[mxatunerjg]

One thing I just thought about in all of this. I think we determined that 2 of the PCM's we've had do this were in cars that had Tazer's installed. We have thought that it could be contributing to the issue, but have not been able to verify

[Homer]

I don't have the tune (changed the FA enrichment rate back to stock) but this the log where my fueling went crazy after I increased the FA enrichment rates to 0.01. Switched it back to stock and car runs fine. BTW I do have a tazer married to the car but never connected when I write or log a tune.

Update, today the SES light for b2s2 O2 slow response popped up. Sure enough, the sensor does not switch as fast as bank 1 (upstream sensors are switching fine and track pretty close to one another). Going to swap the rear sensors to see if sensor it bad...hard to believe since the car has <25k on the clock.