FUSO 4M4 – INTAKE AND EXHAUST – DIESEL PARTICULATE FILTER REGENERATION SYSTEM – Inspection of Electrical Equipment

#038 Inspection of parking brake switch
• Measure continuity between terminals 1 and 2 (body) ground.

• If any fault is found, replace the switch. (See Gr36.)

#089 Inspection of diesel particulate filter cleaning switch

• If there is any abnormality, replace the switch.

#334 Inspection of diesel particulate filter pressure sensor
<Diesel particulate filter differential pressure sensor>
• Apply a 5 volts DC voltage between terminals 1 and 3 of the diesel particulate filter differential pressure sensor.
• Apply air pressures to the sensor and measure the sensor output voltage between terminals 1 and 2 (see illustration).

• If either measurement is out of specification, replace the sensor.

<Diesel particulate filter absolute pressure sensor>
• Apply a 5 volts DC voltage between terminals 1 and 3 of the diesel particulate filter absolute pressure sensor.
• Apply air pressures to the sensor and measure the sensor output voltage between terminals 1 and 2 (see illustration).

• If either measurement is out of specification, replace the sensor.

#336 Inspection of exhaust gas temperature sensor
<Exhaust gas temperature sensor 1>
• The exhaust gas temperature sensor 1 may output false signals if its tip is contaminated. Clean it if necessary.
• Place the sensor in a container filled with engine oil.
• Heat the oil to each of the specified temperatures. Stir the oil well while doing so.
• Measure the resistance between terminals 1 and 2.

• If either measurement is out of specification, replace the sensor.

<Exhaust gas temperature sensor 2>
• The exhaust gas temperature sensor 2 may output false signals if its tip is contaminated. Clean it if necessary.
• Place the sensor in a container filled with engine oil.
• Heat the oil to each of the specified temperatures. Stir the oil well while doing so.
• Measure the resistance between terminals 1 and 2.

• If either measurement is out of specification, replace the sensor.

#338 Inspection of catalytic temperature sensor
• The catalytic temperature sensor may output false signals if its tip is contaminated. Clean it if necessary.
• Place the sensor in a container filled with engine oil.
• Heat the oil to each of the specified temperatures. Stir the oil well while doing so.
• Measure the resistance between terminals 1 and 2.

• If either measurement is out of specification, replace the sensor.