K 1500 Suburban 4WD V8-393 6.5L DSL Turbo VIN S (1996)
EGR Control Solenoid: Description and Operation
Exhaust Gas Recirculation (EGR) Solenoid
EGR Solenoid
DESCRIPTION
The Exhaust Gas Recirculation (EGR) solenoid assembly is locate on top rear of the engine. The Powertrain Control Module (PCM) controls the
EGR solenoid to regulate the vacuum to the EGR valve. By controlling the time the EGR solenoid is "ON" or "OFF" regulates the amount of
EGR. The PCM calculates the amount of EGR based on engine speed and accelerator pedal position. The PCM is programmed to vary the "ON"
and "OFF" time of the EGR solenoid based on these two inputs. To monitor the PCM control of EGR, an EGR control pressure/Barometric
Absolute Pressure (BARO) sensor is used to measure the amount of absolute pressure in the EGR vacuum line. If a minor variation is calculated
EGR and actual EGR as monitored by the EGR control pressure/BARO sensor exists, the PCM makes a correction. If the variation exceeds an
amount in excess of what the PCM can correct for, an error is detected by the PCM and the system will go into default.
When the PCM recognizes the operating range for no EGR, the EGR vent solenoid operates to allow rapid venting of vacuum to the EGR valve.
