HOW TO REPROGRAM CONTROL MODULE - 2003 Saturn L-Series

You don't ,you'll need to take it to a qualified repair shop .

P0605 - Internal Control Module Read Only Memory (ROM) Error Description: The powertrain control module (PCM) ROM has been corrupted. Possible Causes:

• An attempt was made to change the calibration
• Module programming error
• Damaged PCM

Diagnostic Aids: Application Key On Engine Off Key On Engine Running Continuous Memory All Reprogram or update the calibration. Reprogram the vehicle identification VID block (use as built data). Check for other DTCs or drive symptoms for further action. Make sure to check for aftermarket performance products before installing a new powertrain control module (PCM). If it is necessary to install a new PCM, refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) .

Mmmmm.... start here:
2005 saturn vue bcm reprogram Google Search

and this:
http://www.saturnfans.com/forums/showthread.php?t=195610

See this:
2004 saturn bad body control module

then here:
Saturn BCM body control module Removal

Try these YOUTUBES... NOT the same year:
2004 saturn bad body control module

2002 Saturn Veu BCM issue and quick fix
(this MAY help you)?

Anthony

If the HVAC control module is replaced, the following procedure must be performed: Reprogram the HVAC control module. Dealer

Your best bet , take to a GM dealer or some other qualified repair shop . The module would need to be programmed .
Reprogram the transmission control module with the correct calibration. Refer to Service Programming System (SPS) .

Component Name
Preliminary Procedure Remove the left side instrument panel insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side .
1
Body Control Module
Procedure

1. Disconnect the electrical connectors.
2. Reprogram the module if replaced. Refer to Control Module References .

Tip
Push tab to release the body control module from the bracket.

To locate the BCM remove the passenger side instrument panel insulator.Disconnect the negative battery cable. You should be able to see the BCM tucked up behind the dash panel. Will have three wire pack connectors. You have to reprogram the new one when installed. You can not get another, from a salvage yard and make it work. Either go to dealer, or someone who can reprogram it for you. God-Bless!!

ECM, Engine control module. You can't do it. There are shops that can do it, but most likely a dealership.

this might be important for you to know
Quote:

08-08-49-002: False Triggering of Low Coolant Level Warning Message (Reprogram HVAC Control Module) - (Feb 13, 2008)

Subject:
False Triggering Of Low Coolant Level Warning Message (Reprogram HVAC Control Module)

Models:
2007-2008 Chevrolet Silverado 2500 and 3500 Heavy Duty Series Only
2007-2008 GMC Sierra 2500 and 3500 Heavy Duty Series Only
with 6.6L Diesel Engine (VIN 6 -- RPO LMM)

--------------------------------------------------------------------------------
Condition
Some customers may comment that a "COOLANT LEVEL LOW ADD COOLANT" message is displayed in the Driver Information Center (DIC) even though the coolant level is normal.

Cause
This condition may be caused by a false reading during off-road driving or in high slush conditions.

Correction
Do This - Reprogram the HVAC control module.
Don't Do This - Do not replace the coolant level sensor, HVAC control module or radiator surge tank.


A revised calibration has been developed to address this condition. Technicians are to reprogram the Heating Ventilation and Air Conditioning (HVAC) control module with the latest software available on TIS2WEB. Refer to the Service Programming System procedures in SI. As always make sure your Tech 2 is updated with the latest software version.


Warranty Information
For vehicles repaired under warranty, use:
Labor: Operation D4707
Description: HVAC Control Head Module or Assembly Reprogramming with SPS
Labor Time: Use Published Labor Operation Time

You need a dealer or repair shop --with professional tools
& reference material,trouble charts, etc, to diagnose the issues

ECU (engine control unit), ECM (engine control module), PCM (power train control module) VCM(vehicle control module). Basically your vehicle's computer. There are independent shops with the hability and the technology to reprogram it but for sure your manufacturer's dealer.