Cobalt L4-2.0L SC VIN P (2005)
Supercharger Coolant Pump: Testing and Inspection
SUPERCHARGER INTERCOOLER RELAY DIAGNOSIS
CIRCUIT DESCRIPTION
The supercharger (SC) intercooler coolant relay is a normally open relay. The relay armature is held in the open position by spring tension. Ignition 1
voltage is supplied directly to the relay coil and to the armature contact, when the ignition is ON, or the engine is running. The powertrain control
module (PCM) supplies the ground path to the relay coil control circuit, via an internal integrated circuit called an output driver module (ODM).
When the engine is running, the PCM commands the relay ON, and the relay coil creates an electromagnetic field. This electromagnetic field
overcomes the spring tension and pulls the armature contact into the stationary contact of the relay load circuit. The closing of the relay contacts
allows current to flow from the battery to the SC intercooler coolant pump. When the ignition switch is turned to the OFF position, power is
interrupted to the output driver module in the PCM, and the relay electromagnetic field collapses. This allows the spring tension to separate the relay
armature contact from the relay load circuit contact, which interrupts current flow to the SC intercooler coolant pump.
The SC intercooler coolant relay diagnosis is used to diagnose the load circuit supply voltage, the relay contacts, the relay load circuit which includes
the SC intercooler coolant pump, and the ground for the SC intercooler coolant pump.
TEST
