Sensors
Gas detection sensors are located on the cab overhead console (zone 1), in the engine compartment on the frontwall (zone 2), and in the sleeper, if equipped (zone 3). The sensors are located in high areas, where rising gas vapors will pass by or accumulate. On some vehicles, there is a sensor located under the cab floor (zone 4). Zone 4 is not used on DTNA vehicles.
If the system detects that one of the sensors has been disconnected or has malfunctioned, the sensor fault light for that zone will illuminate. A failed sensor may trigger and lock on an alarm. If this happens have a qualified technician troubleshoot the system and make appropriate repairs.
The sensors are sensitive to all hydrocarbon vapors. An alarm may be triggered by the use of chemicals such as cleaners, paint, polish, lacquer, gasoline, silicone, silicone spray, or other harsh chemicals. The sensors will also detect hydrogen fumes from an overcharged battery. If a sensor sends an alarm, but no gas fumes are present, check for recent use of chemicals or a battery charger.
Notice: Silicone-based chemicals and cleaners will permanently disable the sensors. When cleaning the vehicle, cover the sensors with a plastic covering. Keep the sensors covered until the area has been cleared of any cleaning fumes.
Harsh chemicals, including some high alcohol cotenant washer fluids, and extremely high temperatures may damage the sensor.
Puncture of or damage to the seal located inside the sensor housing will significantly shorten the sensor life.
Frequent exposure to high concentrations of gas will accelerate sensor deterioration.