For U Solution

Connect either the high side or low side hose on an A/C servicing station to the appropriate service port. Do not connect a line from the air-conditioning servicing station to the defective port. Evacuate the R134a rigerant into the rigerant tank on the air-conditioning station by turning on the evacuation pump and running it until all the rigerant has left the system.

Disconnect both ends of the line with the defective service port and remove the line. Cover the connections on the A/C system with clean shop rags to prevent dirt and moisture from getting into the A/C system.

Inspect the connections for discoloration. If the connections are clean and slightly oily there are probably no other problems that caused the service port to go bad. Blackened connections could be a sign of internal compressor problems. Investigate further and perform any necessary repairs.

Connect the ends of the replacement line with the built-in service port just as the old line was connected. Ensure that any O-rings or seals at the ends of the lines are replaced and lubricated with mineral oil before the new line is installed.

Connect the other hose from the A/C servicing station to the replacement port. Start the evacuation pump and run it for 15 to 20 minutes to ensure that all the moisture has boiled out of the A/C system. Note the vacuum readout on the A/C station. Allow the system to sit for 10 minutes. Recheck the A/C stations vacuum readout to ensure there is no loss in vacuum. A loss indicates a leak in the system, probably in one of the two replacement line connections. Repair as needed.

Remove the service hose from the high side service port and start the vehicle. Turn the climate control switch to "Maximum." Set the machine to charge the system with R134a and the correct amount of compressor oil through the low side service valve. When enough rigerant is in the system, the air-conditioning compressor will start and draw the rest of the desired amount of rigerant and oil into the system. Remove the low side hose, completing the replacement of the service port.

Put the key into the ignition and turn it to the "On" position, but dont start the engine. Look for the display between the tachometer and the speedometer on the instrument panel.

Press the button on the lower left part of the steering wheel. The display panel will tell you why the vehicle needs servicing.

Find and press the reset button on the left side of the instrument panel. Hold this button for three seconds.

Press the reset button again and hold it until the display says it has been reset. Turn off the vehicle and wait 60 seconds.

Turn on the engine and verify that the service light has turned off.

Check your gas cap. This is a very common issue that triggers an SES light in Nissans. If the gas cap isnt sealed properly or if it was opened while the truck was running, the light will come on. Replace the cap if necessary. If you took the cap off when your engine was running, you can reset the SES light by disconnecting and reconnecting your battery cable.

Diagnose the problem with your vehicle by using a universal code reader. This machine reads the error code your truck is giving, and tells you the corresponding problem for that code. Taking it to a mechanic is always an option, but this usually costs money. Take your truck to an auto parts chain and have your SES diagnostic done for free.

Use the universal code reader by putting your truck into its diagnostic test mode. Turn your ignition on, but do not crank the engine. Depress and fully release the gas pedal five times quickly within five seconds. Wait seven seconds and push the gas pedal down and hold it for 10 seconds. This should cause the SES light to start blinking. Let off the gas pedal. The number of blinks (for example, one blink equals "1," five blinks equals "5," ten blinks equals "0") tells you what error code you have. You can then look it up. After you have your results, hold the gas pedal down for 10 more seconds to erase the memory and reset your SES light.

Put the key into the ignition and turn it to "Run." Dont start the engine.

Press down slowly and fully on the gas pedal, then release it. Do this three times in five seconds.

Watch for the "Service Engine Soon" light to start blinking. This indicates that the system is resetting itself. Turn the ignition to "Off" and wait one minute.

Start the Centurys engine. The Service Engine Soon light will flash for a moment, then turn off. If it doesnt do this, repeat the process.