Fuel Pump Circuit Wiring Diagram (1998-1999 3.1L V6 Buick Century)

APPLIES TO: This fuel pump circuit wiring diagram applies to the following vehicles:

• 3.1L V6 Buick Century: 1998, 1999.

Basic Operating Theory Of The Fuel Pump Relay

The fuel pump relay acts as an electronically controlled switch that allows the PCM (fuel injection computer) to turn the in-tank fuel pump on and off.

When the ignition key is turned to the ON position, the PCM energizes the relay for approximately 2 seconds. This short prime cycle builds fuel pressure before the engine is started.

If the engine isn't cranked during those 2 seconds, the PCM turns the relay back OFF. Once the engine begins cranking and the PCM detects crankshaft position signals, it energizes the relay again and keeps the fuel pump running.

The PCM continues supplying power to the relay only while it detects that the engine is rotating. If the engine stalls or the crankshaft position (CKP) signal is lost, the PCM immediately shuts the relay off, stopping the fuel pump.

If the relay fails, the fuel pump won't receive battery power. This can cause a crank-but-no-start condition or an engine that starts briefly and then stalls.

FUEL PUMP TESTS: How To Test The Fuel Pump (1994-2005 3.1L V6 Buick Century).

Other Fuel Pump Wiring Diagrams

• Fuel Pump Circuit Wiring Diagram (1994-1995 3.1L V6 Buick Century).
• Fuel Pump Circuit Wiring Diagram (1996 3.1L V6 Buick Century).
• Fuel Pump Circuit Wiring Diagram (1997 3.1L V6 Buick Century).
• Fuel Pump Circuit Wiring Diagram (2000-2001 3.1L V6 Buick Century).
• Fuel Pump Circuit Wiring Diagram (2002-2005 3.1L V6 Buick Century).

More 3.1L V6 Buick Century Tutorials

You can find a complete list of 3.1L V6 Buick Century tutorials and wiring diagrams in this index:

• 3.1L V6 Buick Century Index of Articles.

Here's a sample of the tutorials you'll find in the index:

• How To Test The TPS With A Multimeter (1997-2005 3.1L V6 Buick Century).
• Common Causes Of Spark Plug Failure (1994-2005 3.1L V6 Buick Century).
• How To Test For A Blown Head Gasket (1994-2005 3.1L V6 Buick Century).
• How To Test Engine Compression (1994-2005 3.1L V6 Buick Century).