Code B663, Cruise Speed Difference Between Actual And Set, Is Too Large: Notes
Code B663 will set and disengage cruise control if actual speed is 30 MPH higher or lower than set speed. This code is used to set upper and lower limits for operation of the cruise control system, and can be set under normal conditions if operator accelerates, using accelerator pedal and drives 30 MPH greater than set speed. If operator experiences cruise drop out with this code set, but did not accelerate 30 MPH greater than set speed, a mechanical problem is indicated.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- BS05 displays a value representing servo position. The commanded range is normally 0-99 percent. If servo will not go to full stroke, vacuum supply, servo or vacuum brake release circuit is leaking.
- This step checks to see if vacuum leak is due to brake release valve and circuit, or servo and source of vacuum.
- This step checks to see if vacuum leak is due to vacuum source or servo.
- This step checks to see if fault is due to intermittent or slow vacuum leak.
- This step checks to see if fault is servo or brake vacuum release circuit.