'01 Reading flash causes no-start condition

[mike_s]

Got a customer with an '01 duramax, went to read the calibration out of the ECM, initialized to step 2, then mesage "not ready waiting 1 second..." repeatedly. initialized to step 4 then I get a bootloader rejected error after the message that the ECM has "re-armed" after which the truck will not start. Acts like the VATS is active. the truck does start after either removing all the ECM and IGN related fuses or disconnecting the batteries for a period of time.

Customer states that he belives this is due to an ECM update done at the dealership in which they "fried" a certain chip within the ECM to make it non-programmable...I don't buy that. Anyone have any suggestions? I've never had a reading flash cause a no start condition before...

[GMPX]

Customer states that he belives this is due to an ECM update done at the dealership in which they "fried" a certain chip within the ECM to make it non-programmable...I don't buy that. Anyone have any suggestions? I've never had a reading flash cause a no start condition before...

Actually that is true, there has been a problem with GM's programming system and the early LB7's where after they update the ECM it corrupts it.
Usually this would result in you not being able to read the ECM at all, it would say it is locked. Maybe this odd no start is tied in with what happened at the dealers, seems odd though.
The no start condition should not happen on just a read as nothing in the ECM is altered. Just try pulling the battery leads for 30 seconds if it happens again.

Cheers,
Ross

[mike_s]

Good to know! Thanks Ross, guess we'll be looking for him a new ECM...anyone got a line on a source for inexpensive ECM's?

[The Neens]

Good to know! Thanks Ross, guess we'll be looking for him a new ECM...anyone got a line on a source for inexpensive ECM's?

http://socaldiesel.com/2EFILive.htm

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