Quest 1995-1996

Components & Systems

Print

Specific to:

Mercury Villager 1993-2000

Nissan Quest 1993-2000


NOTE
This section describes the operating principles of sending units, warning lights, and gauges. For additional information on sensors that provide information to the Powertrain Control Module (PCM), please refer to the following topics: Driveability and Emission Controls, Electronic Engine Controls, Emission Controls, Engine Control Module.

Instrument panels contain a number of indicating devices (gauges and warning lights). These devices are composed of two separate components. One is the sending unit, mounted on the engine or other remote part of the vehicle, and the other is the actual gauge or light in the instrument panel.

Several types of sending units exist, however most can be characterized as being either a pressure type or a resistance type. Pressure type sending units convert liquid pressure into an electrical signal which is sent to the gauge. Resistance type sending units are most often used to measure temperature and use variable resistance to control the current flow back to the indicating device. Both types of sending units are connected in series by a wire to the battery (through the ignition switch). When the ignition is turned ON , current flows from the battery through the indicating device and on to the sending unit.

Specific to:

Mercury Villager 1993-2000

Nissan Quest 1993-2000


WARNING
Some of the following test procedures require measuring the voltage of Powertrain Control Module (PCM) signal circuits. When testing these circuits, DO NOT allow the voltmeter probes to contact each other or ground, unless instructed to do so. Damage to the Powertrain Control Module and/or the component being tested may result.


WARNING
Some of the following test procedures require connecting voltmeter test probes to the Powertrain Control Module (PCM) electrical connector. DO NOT disconnect the connector when performing the tests and DO NOT allow the voltmeter probes to contact each other or ground. Damage to the Powertrain Control Module may result.


NOTE
To access the PCM electrical connector, remove the glove box and lower instrument panel cover. Unclip the protective plastic cover from the connector to access the wire terminals.

 
label.common.footer.alt.autozoneLogo