Diagnostic Aids
- Inspect for the following conditions:
- Restrictions in the MAP sensor vacuum source.
- MAP sensor seal is missing or damaged.
- Vacuum hoses disconnected, damaged, or incorrectly routed.
- Intake manifold vacuum leaks.
- Vacuum leaks at the throttle body.
- If an intermittent condition exists, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.