Parallel Hybrid Truck Gurgle Noise from Coolant System - kw PHT HP2 SGCM hot heater corepump water

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

On trucks built with RPO "HP2" Parallel Hybrid System, a gurgle noise may be heard from the engine compartment. The SGCM (Starter Generator Control Module) has an independent cooling system from the engine. At times when the SGCM's coolant pump is turned on a gurgle noise may be heard.

This is a normal characteristic and no repairs should be made.

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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. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(04 Chevrolet Silverado) and (04 GMC Sierra)

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