Isuzu 2008MY N Series Workshop Manual page 399

1A-396 Engine Control System (4HK1)
Exhaust Temperature Sensor
The exhaust temperature sensor 1 and 2 is installed to
the DPD housing. Both exhaust temperature sensors
are a variable resistor. The sensor 1 measures the
temperature of the exhaust gas in front of DPD filter
and the sensor 2 measures the temperature of the
exhaust gas in front of oxygen catalyst. When the
exhaust temperature sensor is cold, the sensor
resistance is high. When the exhaust temperature
increases, the sensor resistance decreases. With high
sensor resistance, the ECM detects a high voltage on
the signal circuit. With lower sensor resistance, the
ECM detects a lower voltage on the signal circuit.
Exhaust Throttle Valve & Exhaust Brake Valve
Legend
1. Exhaust throttle valve & exhaust brake valve
MFW4ADSH002401
1
LNW76ESH003701
1
Legend
1. Vacuum inlet
2. Vacuum outlet
3. Vacuum exhaust
4. Solenoid valve
The exhaust throttle valve is installed in rear of the DPD
housing and it composes a part of the exhaust system.
The ECM controls the exhaust throttle solenoid valve
based on the DPD system regeneration status. The
exhaust throttle solenoid energizes to apply vacuum
pressure to the diaphragm chamber to operate exhaust
throttle valve.
The exhaust brake valve is installed in front of the DPD
housing and it also composes a part of the exhaust
system. The ECM controls the exhaust brake solenoid
valve based on the DPD regeneration status or exhaust
brake command signal. The exhaust brake solenoid
energizes to apply vacuum pressure to the diaphragm
chamber to operate exhaust brake valve.
2
4
3
LNW76ESH003601