PIP5085

File in Section:
Service Bulletin
Bulletin No.:
Date:
PIP5085
January, 2013
PRELIMINARY INFORMATION
Subject:
DTC P0420 - Requesting Additional Information If Q57 Indirect Fuel Injector
Replacement is Necessary
Models:
2010 - 2013 Chevrolet Express
2010 - 2013 GMC Savana
2011 - 2013 Chevrolet Silverado
2011 - 2013 GMC Sierra
Equipped with the 6.6 Duramax Diesel Engine (RPO codes LML and LGH)
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Engineering is asking for additional information if SI diagnosis leads to replacement of the Q57 Indirect Fuel Injector
for a P0420 DTC.
SI may also refer to the Q57 Indirect Fuel Injector as the Hydrocarbon Injector (HCI) or the Q57 Exhaust
Aftertreatment Fuel Injector.
In some cases, DTC P2463 may also be stored with the P0420 DTC.
Recommendation/Instructions
If a P0420 is stored, follow the P0420 diagnosis in SI.
If diagnosis leads to the Exhaust Aftertreatment Fuel Injector Diagnosis, document all of your test results.
If Exhaust Aftertreatment Fuel Injector Diagnosis leads to replacement of the Q57 Indirect Fuel Injector, please
document the following information on the repair order to help engineering:
1. Quantity of fuel flow measured (ml) after performing the Exhaust Aftertreatment Fuel Injector Diagnosis.
2. Engine hours as found on the Driver's Information Center (DIC).
3. Type of vehicle/general usage (shuttle bus, commercial vehicle, light duty, hauling, ...).
4. Estimated percentage of time the vehicle spends at idle.
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.