My 2006 H3 Hummer will shut off on its own after about an hour while driving in hot conditions. Coolant temp gage is in normal range. When it shuts down I get a loss power message on display and then shortly after it completely turns off. Unable to restart will not even turn over the starter until about 5 minutest of wait time. Then engine starts and runs fine completely normal except check engine light on. I hooked it up to a scanner to read the error code and freeze frame information. I borrowed the scanner from my father in-law so not sure as to what all the information means but I did look up the error code online. Information below and actions I have taken.

Error code= P0601 Internal control module memory check sum error
Possible causes
1.sensor or solenoid faulty
2.connector terminal contact damage or corroded
3.wire harness
4.update control unit software
5.powertrain or engine control module
6.battery voltage low

Freeze frame info=
Engine speed (1/min)= 669
fuel system 1= closed loop
fuel system 2= not used
intake air temp=70
engine coolant temp=91
air flow rate (g/s)=4.87
intake map(kpa)=38
Ignition timing advance=11.0
short term fuel bank(1%)= -.07
long term fuel bank (1%)=14.1
vehicle speed (MPH)=0
Calculated load value=36.5

Things I have done to troubleshoot issue with no positive result.
1. Ran engine about an hour till it shut down. Tried restart no go. Poured cold water on engine control module until cool to touch and tried to restart. No start. waited 5 minutes. Tried restart and engine starts with check light. Drove home shut off engine. Restart engine no engine check light runs fine. The ECM was not extremely hot like they said it would be if it was possibly failing. But, I ran the test anyway.

2. Voltage tested the battery. Cables looked clean. Engine off voltage =12.6, engine on voltage =13.4.

3. I plan on getting electrical connector cleaner and pulling cables off of ECM check for damage, clean and reinsert.

Any help on what to do next and what you believe the problem may be will be greatly appreciated.

Thanks,
Josh

 

Hi langj

Have you tried a new battery & battery connectors? If they are original oem...
Also 13.4 seems low. Happy puts out 14.5-15.4v running.

Chris

 

Do you have a sunroof? If so, have you gotten the passenger side floor wet?

If you still have the OEM battery terminals, hack them off and replace them with a good quality aftermarket set, like Stingers. Do it ASAP.

 

A bad battery and old terminals can put out some crazy codes and might be a good cheap first step. Also I don't know if the scangauge II can wipe out codes but the Bullydog Watchdog system can and gives you a lot of great info.

 

I just dealt with this exact problem. It is your pcm failing. I thought no way, but in the end it was. I got a new one for $100 from flashmasters. It does have a crank position relearn code noe, that can only be cleared by the dealer, but it doesn't effect the way the truck runs and the dealer wants $100 to clear it, so waiting on that for now. Code p0601 is a faulty pcm and cannot be reflashed. A p0602 is a faulty pcm that can be reflashed. I would replace it soon because it will completely stop working eventually.

 

I am having some seroius issues with h3. While reading the post here Doc Olds ask the question Did you get the passenger floorboard wet? I did and was wondering what the consequences would be. I am getting the "traction failed serv stab sys" message. When i hook up the reader i am getting the P0601 ECM. It will crank and stay running about two seconds then die. i then have to wait about ten seconds before it will crank again. Any help will be greatly appreciated

 

Thanks for the info. I just had mine checked today with the P0601 code showing up. It will die then eventually crank after a short period. Loosing all power in the middle of traffic is pretty serious. Going for a pcm tomorrow at the dealer. Anyone have an idea of how much one might cost? Thanks!

 

hi
i have the exact same problem, was wondering if you came with a solution, would really appreciate the help, thanks!

 

Did I not already ask you to Please stop digging up OLD threads in your last necro-bump? .... and provide this link
https://www.hummerforums.com/forum/n...bumping-23220/

Use the SEARCH function.

Did you read this one before digging it up from almost 3 years ago? One of the most common cause of H3 electrical issues is the OEM battery terminal connectors are crap, they always fail at some point. Did you replace them yet?
Try that, then post up a NEW thread with your question.