Fix for LS2 E40 PCM with a P0601 code

[us1us1]

I have an 2006 Trailblazer SS LS2. It has an E40 PCM. Always ran great. I killed the battery the other day and slapped a battery charger on it. Well the charger was way too many volts and after the charge the PCM started throwing P0601: an Internal Control Module Memory Checksum Error code. The motor would die at idle. I would shut it off and after two minutes it would start again. 20 miles or so later it would do it again.

Luckily I just got HP Tuners and saved my tune file while everything was still working good. I figured what have I got to loose so I did a FULL rewrite of the PCM and it totally fixed the problem. Maybe other already know this but after searching the internet for 2 weeks I found nothing but P0601 means new PCM. Not so in my case.

[5FDP]

Don't shocked if the fault somehow comes back though.

[us1us1]

I'll keep you posted if it does. I already have another PCM on the way just in case. I ordered it before I fixed this one.

[us1us1]

Just thought I would check back in and let you all know that four months later the problem is still gone. A full rewrite of the PCM software can fix a P0601 code if you have a clean file to write to the PCM.

[jaydubb71]

Clean file?

[us1us1]

Clean file?

Meaning a good known file not one you have read from the damaged PCM.

[jaydubb71]

Meaning a good known file not one you have read from the damaged PCM.

Does that require a VIn change? Im dealing with a bricked E40 in a GTO right now. Would you mind checking out my thread? Its called "Stinking E40!". Thanks in advance.

[us1us1]

No, you don't need a vin change. Hopefully you read and saved your tune file before there was any malfunction.

[jaydubb71]

No, you don't need a vin change. Hopefully you read and saved your tune file before there was any malfunction.

Yes, I saved the tune file. This ECM had been previously flashed with a Diablo Trinity. I got this GTO running great but it would rev above 6000. I have all of the limiters set to 6600. This is the first one Ive seen like this. I tried a WRITE ENTIRE to try to correct the rev limiter issue but during the erase process, it timed out. Now it wont start and the check engine light wont come on.

[us1us1]

I hate to same it but it sounds bricked. The only way I know to fix that is rechip the PCM or replace the whole thing.

[ranormsbee]

Rookie Tuner Here
I have a 2011 GMC with 5.3 ,Comp Cam 189-400-13,AFM Delete,VVT with a limiter wedge for valve to piston clearance. And my Own Tune.
Yeterday while idling at a stop light the engine just shut off and would not restart (no cranking).opened the hood and did a visual inspection with nothing found out of place.
Got back in and it restrted,drove away from the intersection and it shut off again.Disconnected the MAF thinking it might have failed and was able to drive it home and do a scan.
P0601 stored .
So after reading this Post I decided to do a full rewrite of my last tune this morning.
Went for a good drive and it appears to be fixed.Hopfully this can save someone else the cost of an ECM

[blindsquirrel]

That's great, as long as none of the corrupted bits live in the two TAC segments of the ECM that HP Tuners does not read or write. To do a real true honest ground-up reprogramming on these you have to use SPS.

[ranormsbee]

Great Good to Know

[ranormsbee]

How many times can you use write only before you have a problem like I did and have to use Write Entire?

[blindsquirrel]

Somewhere between infinity times and once.

[ranormsbee]

So how would the file become corrupted being that I have Made Dozens and Dozens of tune changes over the past year without ever having a prolem?

[ranormsbee]

The only Change was using Beta because some Controls and Functios would not work
I have since removed the Beta scaner and editor

[blindsquirrel]

Cosmic ray strike? Some other seemingly unrelated module in the car woke up or went to sleep while flashing and it put a tiny bit of noise on the ECM's power rail and it just glitched? Shit happens sometimes. Or doesn't. There's some amount of risk in starting the engine, much less tinkering with the ECM code and backyard reflashing. If you think this is supposed to be foolproof and nothing should ever go wrong you need to recalibrate your Risk-O-Meter.

There's risk in reprogramming even in a proper dealership-type setting when using dealer-type tools and a real proper power supply on the battery. I feel like this is getting close to seeing a question like 'but How are they Allowed to Sell this if there's a chance It could brick your Car?'

[ranormsbee]

Great explanation ..... I totally agree "SHIT HAPPENS" Thanx.