Cavalier/Z24 L4-138 2.3L DOHC VIN D MFI (1995)
Coolant Level Switch: Description and Operation
Coolant Level Switch Location
DESCRIPTION
The coolant level switch is connected to the Powertrain Control Module (PCM). If a low coolant level condition is detected, the PCM will send a
signal to the Instrument Panel Cluster (IPC). The IPC will receive this signal from the PCM and the IPC will then illuminate the warning lamp.
The electronic instrument cluster utilize a "Low Coolant Level" telltale lamp that indicates a low coolant level condition. The purpose of this lamp
is to warn the operator of a potential engine damaging condition. If the warning lamp is illuminated, then a condition is present that may cause
engine damage.
OPERATION
The coolant level switch is an assembly containing a reed switch and magnetic float. When the coolant level is normal, the float rests away from
the reed switch, causing the switch to open. When the coolant level is low, the float rests near the reed switch and the switch closes.
The coolant level switch is mounted in the radiator surge tank to monitor radiator coolant level. The coolant level switch is a normally open
switch. If coolant falls below a specified level, the switch closes sending a ground signal to the PCM. The PCM in turn will send information
through serial data to the instrument cluster. The cluster will then turn "ON" the low coolant level telltale.
