Avenger L4-2.0L DOHC (1995)
Engine Control Module: All Technical Service Bulletins
PCM - Whistle Type Noise
NO: 18-13-95
GROUP: Vehicle Performance
DATE: Apr. 21,1995
SUBJECT:
Whistle Noise From PCM
MODELS:
1995 (FJ) Avenger/Sebring/Talon (2.0L DOHC, MTX)
1995 (PL) Neon
DISCUSSION:
The PCM (Powertrain Control Module) may emit a high-pitched "whistle" sound after the engine is shut off. The sound may last up to eight minutes. The
noise can vary in pitch and intensity from one PCM to the next and with changes in temperature and battery system voltage.
This noise is due to the PCM being "powered up" after ignition off to enable a diagnostic routine for the O2 heater operation. This diagnostic routine will
only occur when certain parameters are met, which include engine operating temperature and how long the vehicle has been driven. This noise may also
be heard with the ignition on and engine running, but is usually muffled by the normal engine operation sounds.
Replacing the PCM may seem to eliminate the noise for a period of time, but this is only due to the system not meeting the qualifying parameters to run
the ignition off diagnostic routine.
NOTE:
THIS IS AN OPERATIONAL CHARACTERISTIC OF THE PCM AND NO REPAIRS SHOULD BE ATTEMPTED.
POLICY: Information Only
