Cutlass V6-260 4.3L DSL (1984)
Exhaust Pressure Regulator Vacuum Valve: Testing and Inspection
EPR Electrical Check
Fig. 038 - WIRING DIAGRAM for EPR Electrical Check. VIN T, VIN V
EPR ELECTRICAL CHECK
The EPR solenoid controls vacuum to the EPR valve. The EPR solenoid, when energized, allows engine pump vacuum to close the EPR valve. The
same vacuum source is used for both EGR and EPR solenoids. 12 volts is supplied from the ignition, and the ECM completes the ground to energize the
solenoid. The ECM will not recognize an electrical fault in the EPR circuit, but will detect a vacuum leak causing no EPR. The EPR is turned "OFF" by
the ECM when engine temperature is below 52°C (125°F). The engine temperature switch, when closed, signals the ECM that the engine is cold.
