Engine Mount (Active Control) - System Diagnosis: Overview
ENGINEEG003-99
Title:
ACTIVE CONTROL ENGINE MOUNT
SYSTEM DIAGNOSIS
Models:
'99 RX 300 & ES 300
June 18, 1999
Introduction
The following procedure should be used to diagnose the Active Control Engine Mount System.
Affected Vehicles
1999 RX 300s and ES 3005
Description
The Active Control Engine Mount (ACM) System dampens engine vibration at low engine speeds using the ACM VSV. The ACM VSV is controlled by a pulse signal transmitted from the Engine Control Module (ECM). In normal operation, the frequency of this pulse signal is matched with engine speed to effectively dampen engine vibration.
Active Test
The ACM Inhibit Active Test should be used to verify proper function of the ACM System.
When the ACM Inhibit Active Test is enabled, the pulse frequency transmitted from the ECM to the VSV is not correctly matched to engine speed. As a result, the technician should observe an increase in engine vibration.
Correct functioning of the ACM System is indicated by excessive vibration while the ACM Inhibit Active Test is in the "ON" state. If excessive vibration is not observed, then the ACM System is not functioning correctly.
Warranty Information