Component Description

A/T fluid warmer

• The A/T fluid warmer (1) is installed on the front part of cylinder block of engine.
• When engine is started while engine and A/T are cold, engine coolant temperature rises more quickly than A/T fluid temperature. A/T fluid warmer is provided with two circuits for ATF and engine coolant respectively so that warmed engine coolant warms ATF quickly. This helps shorten A/T warming up time, improving fuel economy.
• A cooling effect is obtained when A/T fluid temperature is high.
  Fig 1: Identifying A/T Fluid Warmer

  Courtesy of NISSAN NORTH AMERICA, INC.

A/T fluid cooler (with bypass valve

• A/T fluid cooler (1) is installed in the front of radiator (2) and condenser (3).
• A/T fluid cooler is provided with a bypass valve that controls ATF flow. Bypass valve operates by thermo wax and a return spring. Bypass valve fully opens when A/T fluid temperature is approximately 90°C (194°F) and fully closes when A/T fluid temperature is approximately 100°C (212°F).
  Fig 2: Identifying A/T Fluid Cooler, Radiator And Condenser

  Courtesy of NISSAN NORTH AMERICA, INC.
• When A/T fluid temperature is low, the bypass valve is open. Most of ATF therefore returns to the transmission without flowing into the cooler core that has larger flow resistance.
  Fig 3: A/T Fluid Cooler Bypass Valve Operation Diagram (Fluid Temperature Low)

  Courtesy of NISSAN NORTH AMERICA, INC.
• When A/T fluid temperature rises [to approximately 100°C (212°F)], bypass valve closes and allows ATF to flow into cooler core. ATF flowing into cooler core is cooled by air stream caused by vehicle travel and returned to transmission.
  Fig 4: A/T Fluid Cooler Bypass Valve Operation Diagram (Fluid Temperature Rises)

  Courtesy of NISSAN NORTH AMERICA, INC.