A/C - Poor Low Speed 2nd/3rd Row Heater Performance
Bulletin No.: 04-01-39-002Date: February 26, 2004
ADVANCED SERVICE INFORMATION
Subject:
Poor Heater Performance - 2nd and 3rd Row Seats
Models:
2004 Buick Rainier
2002-2004 Chevrolet TrailBlazer EXT
2002-2004 GMC Envoy XL
2002-2004 Oldsmobile Bravada
Condition
Some customers in colder climates may comment on inadequate heat for passengers seated in the second and third rows.
This is most noticeable while operating the vehicle at slower engine speeds and/or at idle.
Cause
This condition is most likely due to a significant coolant temperature loss during periods of slower flow from the engine to the rear heater core.
Correction
NO REPAIRS SHOULD BE MADE AT THIS TIME.
This condition is considered a normal operating characteristic of the vehicle. Engineering is investigating options to improve the rear heat system effectiveness. This bulletin will be updated with additional information that will be communicated when the engineering activities are complete.
Refer to SI - HVAC Description and Operation information to help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation.
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