Circuit/System Description

The K27 fuel pump control module receives accelerator pedal position transmission gear and RPM information via serial data from the K20 engine control module. The K27 fuel pump control module uses this information to determine a target position for the tailpipe exhaust valves. To achieve the target position, the K27 fuel pump control module commands the KR146 exhaust flow control valve relay ON or OFF. When commanded ON, the KR146 exhaust flow control valve relay opens the Q15 exhaust flow control valve solenoid, which exposes the left and right tailpipe exhaust valves to vacuum. When exposed to vacuum, the tailpipe exhaust valves will close. When commanded OFF, the KR146 exhaust flow control valve relay closes the Q15 exhaust flow control valve solenoid, which isolates the left and right tailpipe exhaust valves from vacuum. In the absence of vacuum, the tailpipe exhaust valves will open.