E030 is ISC RPM out of Range, Code E030 is set because the actual RPM never reaches desired RPM signifying a slow or failed ISC motor. ISC is the the Idle Speed Control motor. Faults include checking proper throttle switch, brake switch and park/neurtal switch operation, proper ISC motor operation, and engine and fuel emissions faults may cause unstable idle. My guess due to the E048 is that your EGR is hung open, how is your idle, should be very rough or stalling.. E048 is the EGR system