2003 Nissan-Datsun Sentra SE-R, AutomaticFACTORY OEM SERVICE PROCEDURE

Circuit Description

WARNING: This page is about a different car, the 2002 Isuzu Trooper, 2002 Isuzu Rodeo Sport, 2002 Isuzu Rodeo, 2002 Isuzu Axiom, and 2002 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.

When air conditioning and blower fan are selected, and system has a sufficient refrigerant charge, a 12-volt signal is supplied to the A/C request input of the PCM. A/C request signal may be temporarily canceled during system operation by the electronic thermostat in the evaporator case. When A/C request signal is received by PCM, PCM supplies a ground from A/C compressor clutch relay if engine operating conditions are within acceptable ranges. With A/C compressor relay energized, voltage is supplied to the compressor clutch coil. PCM will enable the compressor clutch to engage whenever A/C has been selected with engine running, unless any of the following conditions are present:

  • Throttle is open 90% or more.
  • Ignition voltage is less than 10.5 volts.
  • Engine speed is more than 4500 RPM for 5 seconds.
  • Engine coolant temperature 257Β°F (125 Β°C) or more.
  • Intake air temperature is less than 41Β°F (5Β°C).
  • Power steering pressure switch signals a high pressure condition.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.