Service VME - 3-2 Downshift Buzz Noise on 2004 and 2005 Police Impalas Equipped with the 3800 V6 Engine and the 4T65E Transmission - keywords brake cooler L26 L32 L36 L67 line rattle shift steering

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

This Service VME to all Chevrolet dealers concerns a 3-2 downshift buzz noise on 2004 and 2005 Police Impalas equipped with the 3800 V6 engine and the 4T65E transmission also equipped with an auxiliary transmission cooler. This noise is most noticeable during moderate braking maneuvers and could be best described as a noise similar to an ABS test cycle. Use of chassis ears may result in isolation of the noise to the transmission cooler line. If no contact is observed between the auxiliary cooler line and the lower radiator support the noise is most likely from the transmission. Repairing or replacing the transmission components will not resolve this concern. Engineering is aware of this concern and are currently working to root cause and resolve. If at all possible do not perform a repair attempt. You will be notified when the field repair becomes available. This VME comes to from Darryl Butler BQM 4T65E transmissions.

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.

(2004-2005 Chevrolet Impala)