Symptoms. Buick GL7 (Export) 2000

For 1990-2009 cars

### Important Preliminary Checks Before Starting

Before using the Symptom tables perform the following preliminary checks:

• | Perform Powertrain On Board Diagnostic (OBD) System Check and verify all of the following conditions:

• | The PCM and the malfunction indicator lamp (MIL) are operating correctly.

• | There are no DTCs stored.

• | The scan tool data is within the normal operating range. Refer to Scan Tool Data List .

• | Verify the customer complaint.

• | Perform the Visual/Physical Check in this section.

Locate the correct symptom in the list at the end of this section. Follow the procedures in the appropriate diagnostic table. If the problem can not be duplicated, refer to Intermittent Conditions .

### Visual/Physical Inspection

Notice: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:

• | The PCM harness connectors

• | The electrical center fuse/relay cavities

• | The component terminals

• | The component harness connector

Using this kit will prevent damage caused by the improper probing of connector terminals.

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

• | Inspect the PCM grounds for being clean, tight, and in their proper location. Refer to Electrical Center Identification Views , Power and Grounding Component Views , and Power and Grounding Connector End 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 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.

• | Inspect the aftermarket/after factory add-ons and accessories for correct installation. These accessories may lead to an emission related failure while in use, but do not fail when the accessories are not used. Following the manufacturers instructions do not gaurantee the accessories will not interrupt the vehicles normal operation as manufactured.

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

• | Rough, Unstable, or Incorrect Idle and Stalling

• | Dieseling, Run-On

• | Backfire

• | Restricted Exhaust System Check