Test Description

WARNING: This page is about a different car, the 1995 Oldsmobile Ninety-Eight and 1995 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Test numbers refer to numbers on diagnostic chart.

Checks servo position sensor. If signal is not being received at PCM, use Code P1565 to diagnose problem.
Verifies vacuum portion of cruise system is operational.
Checks for faulty brake switch.

Fig 1: Code P1558 Schematic (3.8L) Cruise System Problem SPS Indicated Low

Fig 2: Code P1558 Diagnostic Flow Chart (3.8L) Cruise System Problem SPS Indicated Low