Programming Hints - ECM - keywords 05524A DTC reprogram

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

If vehicle is difficult to reprogram, review these hints.

Programming Hints - ECM for HFV6 LY7 / LP1 in CTS, STS, SRX, Rendezvous, LaCrosse/Allure:

1. Be sure Tech 2 and TIS have latest updates
2. Due to the large download file size, programming takes a long time, possibly leading to battery drain issues Use battery boost box (DC) or jump to another vehicle. A new Kent Moore battery charger is coming soon (better DC control)

Perform self test on Tech 2 and CANdi module prior to beginning, as a check of cables etc. LED on CANdi module should be flashing about once per second Be sure all tester cables are o.k.; maintain good connection to vehicle for the entire programming time.

Pass thru programming, TIS may say successful when Tech 2 still is not finished programming. The TIS screen only refers to data transfer from TIS to the Tech 2, actual vehicle programming status is on the Tech 2 screen

GMX295 must have "key on" on to program (hold button for 5 sec) otherwise a Tech 2 programming error message occurs in about 5 min.

2004 ECMs will be "locked" if battery voltage drops or programming is interrupted during the programming process. It may be worth while to try programming again to verify, but if locked, 2004 ECMs are not recoverable from this condition.

2005 ECMs will not become locked, and can be programmed even if an interruption occurs during programming. If interrupted, just start back at the beginning of the procedure (getting vehicle I.D. again for TIS) and try again.

On 2004 vehicles:

After reprogramming, the engine can be started, but the VTD light will flash, meaning VTD is not functional at all. Perform "Clear DTCs" to reset VTD and prepare it for learning a new VTD password. The VTD light then is solid on and the car will not start until a new password is learned. Then perform "VTD learn procedure"

If there are any interrupts, the VTD light is flashing, steady on, or the car will not start, perform a "clear DTC" and try again to learn the VTD password.

If the 10 min Tech 2 VTD learn does not work it may be due to an older version Tech 2 software or an older version of TIS software. If there are problems with the Tech 2 10 min. VTD password learn procedure; try the 30 min. procedure (3x10 min. without the Tech 2)Be sure battery voltage is maintained throughout the entire process.

To verify successful reprogramming, read out new cal part numbers from the vehicle after everything has been finished.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.