Duramax Diesel Engine Turbocharger Learn Procedure - keywords DTC ECM LLY P0045 P0046 P2563 P2564 relearn turbo

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

When completing SI diagnostics on the 2004 to 2005 6.6L LLY turbocharger, you may be directed to the turbocharger learn procedure. The technician may also find the turbocharger learn parameter does not change or fluctuates from YES to NO.

1. The turbo relearn status may or may-not change to yes after the criteria for turbo relearn is completed.
2. The "YES" / "NO" status not changing or fluctuating is a Tech 2 software issue and the turbo position may have already relearned.
3. If the vehicle was brought in for a turbo trouble code, or an engine driveability symptom that is caused by the turbo, complete the current SI diagnostics for the trouble code or symptom found.

The turbocharger relearn will occur automatically.

Use the current SI information for a description of the Turbocharger Learn Procedure.

Please follow this diagnosis 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.