Code P1558, Cruise System Problem SPS Indicated Low: Notes
WARNING: This page is about a different car, the 1994 Oldsmobile Ninety-Eight and 1994 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.
PCM controlled cruise control system is designed to be self monitored to ensure desired cruise servo position and actual cruise servo position are equal to one another. PCM will set Code P1558 when actual servo position is too low when maximum servo is commanded.
Code P1558 will set when the following conditions are present.
- Throttle angle less than 50 percent.
- Desired servo position is 90 percent.
- Actual servo position is less than 2 percent.
- Above conditions for 3 seconds.
If Code P1558 is set, PCM will disengage cruise control and C/C set speed exceeds vehicle speed by greater than 5 MPH. P1558 does not illuminate the Malfunction Indicator Light (MIL).