Diagnostic Aids
WARNING: This page is about a different car, the 1994 Pontiac Bonneville, 1994 Oldsmobile Eighty-Eight, and 1994 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Code P1558 may set if cruise control throttle cable binds or intermittently sticks. Outside interference such as a CB antenna lead near PCM wiring harness may induce a false SPS signal and set Code P1558.
An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside insulation. Check for:
- Poor Connection Or Damaged Harness: Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.