QuestionHi
I have a 2000 Cadillac Deville.Its a used car that I bought about 8 months ago.Just recently the service engine light came on and shortly there after the battery not charging message came on. The battery dead acouple days later and i had a buddy come over and hook it up to the computer. The only code that it spit back was p0601 (internal control module memory checksum error). i bought a brand new battery put it in and every message went off for a day then came back the next day. now its dead again. I'm stuck and really don't want to take it to a shop if i don't have to. what does the code mean cause everything i read online confused me? Does that have anything to do with an ECU Chip? and would that effect my battery/alternator? thank you very much for your time and help!
AnswerYou must replace the PCM.
PLEASE READ the below information:
Some PCM's come PRE-PROGRAMMED or FLASHED by the manufacturer or rebuilder for your particular vehicle. Before you purchase a new PCM, ASK if it has been PRE-PROGRAMMED or FLASHED by the manufacturer or rebuilder for your particular vehicle. If it has NOT, You must have a reputable facility who has the proper equipment to do this procedure.
Starting in 2000, flash reprogramming procedures must also conform to SAE J2534 standards that allow the use of aftermarket scan tools or similar pass-through devices.
Reflashing PCMs requires three things: a scan tool or J2534 pass-through device that is flash capable, a Windows 98 or higher PC with a modem and Internet access for downloading the flash software from the vehicle manufacturer's website (Click Here for a list of OEM Service Websites & Access Fees), and a subscription to the manufacturer's database so you can access the software or get the software updates on CDs. Other items that are needed include a cable to connect the PC to the scan tool or J2534 pass-through device, and a cable to connect the scan tool or J2534 pass-through device to the OBD II connector on the vehicle.
For GM applications, you need a Tech 2 scan tool or Vetronix Mastertech.
Yearly and monthly access fees to OEM databases tend to be very pricey for the average shop, but one-day or short-term access fees are typically available for $20 to $25. The cost can and should be passed along to your customers. After all, it is their PCM that is being reflashed so why shouldn't they pay the OEM software access fee?
On GM and Chrylser applications, flash updates are supplied on CDs once you pay a subscrption fee. With Ford, the softare is downloaded from their website via an internet connection. The software is then loaded from the CD to your PC. From here, the software may be copied to a flash card which is then plugged into a scan tool for transfer to the vehicle, or it is copied through the J2534 pass-thru box or scan tool to the vehicle. With Ford, you have to keep a live internet connection for the duration of the procedure because Ford loads the software into the vehicle directly from its own server).
The flash procedure can takes from a few minutes up to an hour depending on the file size of the softare you are installing. The newer and more complex the vehicle, the longer it typically takes to flash the PCM.
Did You Know...
Some of the other players you can expect to see in the flash reprogramming arena include Hickok Tools , CARDONE Industries , Drew Technologies and OTC Div of SPX Corp.
GM Flash Updates
On GM vehicles, a list of flash updates that are available can be found on GM's Vehicle PCM Calibration Information website at http://calid.gm.com or http://tis2web.service.gm.com/tis2web
The actual reprogramming procedure for a typical GM vehicle goes as follows:
Check the calibration history of the vehicle -- Go to the GM web page at http://calid.gm.com or http://tis2web.service.gm.com/tis2web to see what latest program is for the vehicle by entering the vehicle VIN number. If the programming has been updated, the most recent calibration will be listed on the website. You can't download the new calibration software from the website,however. You must first purchase a TIS subscription from GM, and then GM will mail you the calibration softare on a CD. The software can then be copied from the CD through your PC to a flash card for the Tech 2 scan tool.
Connect your PC to the Tech 2 scan tool with a RS232 cable pass-through device.
Before you start the procedure, make sure the battery is fully charged. You do NOT want any loss of voltage during the procedure as this can reallys screw things up! GM does NOT approve using a battery charger, unless it is a GM-approved Midtronics charger (which delivers very consistent voltage with no fluctuations). On some vehicles, removing the fuses for the fan relays, fuel pump or other modules may be required to prevent these devices from turning on during the procedure.
Start the GM recalibration software program on your PC (which you have to purchase from GM, along with the update CDs) and enter the vehicle application information (year, make, model, etc.).
Connect the Tech 2 scan tool to the diagnostic connector on the vehicle (located under the dash near the steering column).
Switch the Tech 2 scan tool on and wait for the Start screen.
Validate the vehicle VIN number.
Choose the operating system, engine, fuel system, speedometer or transmission.
Select "normal reprogramming" or "VCI" (special modifications).
Choose the update bulletin/recalibration number from the menu.
Start the transfer of data. As the software is loaded, you will see a progress bar. The reprogramming procedure may take a new minutes to 30 minutes or more depending on the file size, and can be done with the computer in or out of the vehicle. The PC screen will display a blue progress bar as the software is uploading to the vehicle.
Note: The GM setup will NOT allow the same calibration to be reinstalled over itself. Only an updated calibration can be loaded into the vehicle computer. There is no going back to an earlier version.
When the software has finished loading, the message "PROGRAMMING COMPLETE" will appear.
Turn the ignition OFF, then disconnect the scan tool. Depending on the application, it may be necessary to run one or more "relearn" procedures before the PCM will function properly. Most GM PCMs require a "CASE" relearn so the PCM can learn the relative positions between the cranshaft and camshaft sensors. If you don't do the CASE relearn, the Check Engine Light will come on and there will be a code P1336.
Not Without Risk
So what happens if something goes wrong during a reflash procedure? Anyone who has ever experienced a crash while installing new software on a PC knows it can cause real problems. In some cases, the PCM may be so scrambled that it will not accept a reflash, which means you get to buy a new PCM!
Doing your own flash reprogramming is not without risk. But for some shops it may be a more practical and profitable alternative to sending vehicles back to the dealer when a PCM needs to be updated or replaced.
Some vehicles with driveability problems that have NO CODES displayed can benefit by having the EEPROMS reprogrammed with updated information put out by the vehicles manufacturer and performed by a reputable facility or a dealer.
