ECM NH3 5250, Instruction Manual, Page: 15 / 62

11
Mounting the NH
3
Sensor

NH
3
Sensor

Thread is 18mm x 1.5mm

Mount downstream of the SCR (Selective Catalytic Reduction) catalyst or where
there are not significant amounts of CO (carbon monoxide). This is due to the
sensor’s cross-sensitivity to CO. To avoid reversion effects, mount at least ten
exhaust diameters upstream of exhaust end.

Do not exceed 450 °C exhaust gas temperature at location of sensor.

Mount where condensed material will not collect on the sensor (ex. if the section of
exhaust pipe where the sensor is to be mounted is parallel to the ground, the sensor
should be mounted on the upper half of the pipe).

Run tap into thread of mounting boss before screwing in sensor.

Put antiseize on threads and lightly tighten sensor.

Occasionally run tap through mounting boss to clean threads.

Occasionally clean threads on sensor with small metal brush.

Do not operate engine with NH
3
sensor not being powered.

Route NH
3
sensor cable away from hot, moving, sharp, or high voltage (spark) wires.