Visual/Physical Check

Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a condition without further tests and can save valuable time. This inspection should include the following areas:

• Inspect the powertrain control module (PCM) grounds for being clean, tight, and in their proper location. Refer to Master Electrical Component List and Power and Grounding Component Views in Wiring Systems.
• Inspect vacuum hoses for splits, kinks, and proper connections, as shown on Vehicle Emission Control Information label. Inspect thoroughly for any type of leak or restriction. Refer to Emission Hose Routing Diagram .
• Inspect the air intake ducts for being collapsed, damaged areas, looseness, improper installation, or leaking, especially between the mass air flow (MAF) sensor and the throttle body.
• Inspect for air leaks at throttle body mounting area, mass air flow (MAF) sensor and intake manifold sealing surfaces.
• Inspect the wiring harness for poor connections, pinches, cuts, or other damage.
• Inspect for loose, damaged, or missing sensors/components.

Use the following tables when diagnosing a symptom complaint:

• Hard Start 
• Surges/Chuggles 
• Lack of Power, Sluggishness, or Sponginess 
• Detonation/Spark Knock 
• Hesitation, Sag, Stumble 
• Cuts Out, Misses 
• Poor Fuel Economy 
• Poor Fuel Fill Quality 
• Rough, Unstable, or Incorrect Idle and Stalling
• Dieseling, Run-On 
• Backfire 
• Engine Cranks but Does Not Run (with Supercharger)  or Engine Cranks but Does Not Run (without Supercharger) 
• Malfunction Indicator Lamp (MIL) Inoperative 
• Malfunction Indicator Lamp (MIL) Always On