Fuel Tank Pressure And Temp. Sensor Inspection

NOTE: For clarification the Fuel Tank Pressure Sensor and Temperature Sensor are housed in the same sensor body.

Remove fuel tank pressure and temperature sensor from fuel tank.
Check sensor air vent hole and pressure passage for clog. Clean if clogged.
Check sensor O-ring for damage and deterioration. Replace as necessary.

Fig 1: Checking Sensor O-Ring For Damage & Deterioration
Courtesy of SUZUKI OF AMERICA CORP.
Arrange 3 new 1.5 V batteries (2) in series (check that total voltage is 4.5-5.0 V) and connect its positive terminal to "A" terminal of tank pressure and temperature sensor (1) and negative terminal to "B" terminal. Then check voltage between "C" and "B"
Also, check if voltage reduces when vacuum is applied up to 6.6 kPa (50 mmHg) by using vacuum pump (3) and if it increases when positive pressure applied up to 6.6 kPa (50 mmHg) by using hand pump.

If measured voltage doesn't show such characteristic as shown in the figure, replace fuel tank pressure and temperature sensor.
CAUTION:
- As connection to wrong terminal will cause damage to tank pressure and temperature sensor, make absolutely sure to connect properly as shown.
- Do not apply pressure higher than 98 kPa (742 mmHg) to tank pressure and temperature sensor by hand pump. Applying excessive pressure will break it.
Fig 2: Inspecting Fuel Tank Pressure Side Of Fuel Tank Pressure & Temperature Sensor
Courtesy of SUZUKI OF AMERICA CORP.
Immerse temperature sensing (1) of fuel tank pressure and temperature sensor (2) in water (or ice) and measure resistance between sensor terminal "A" and "B" while heating water gradually.
If measured resistance doesn't show such characteristic as shown in the figure, replace Fuel Tank pressure and temperature sensor

Fig 3: Inspecting Temperature Side Of Fuel Tank Pressure & Temperature Sensor
Courtesy of SUZUKI OF AMERICA CORP.