The Coolant Level Sensor (CLS) is required for DDEC IV installations. Its purpose is to provide an input to the engine protection system and warn the operator if a low coolant level has been reached. Other non-DDC supplied coolant level sensors may be used, but may require the use of a signal interface.
The main component of the CLS consists of a conductivity probe that connects to the ECM. See Figure 3-31.
The connector listed in Table 3-6, is a Metri-Pack 280 series push-to-seat connector.
The OEM must connect the CLS probe as shown; see Figure 3-32. Polarity of the ground and signal must be correct for proper operation.
The CLS probe connects to the engine interface harness quick disconnect connector on many multi-ECM engines. Refer to section 2.3.7.
The probe should be located in either the radiator top tank or a remote mounted surge tank. It should be mounted horizontally in the center of the tank, and must be in a position to signal low coolant before aeration occurs. Typically, this is a height representing 98% of the drawdown quantity. The probe should be located so that it is not splashed by the deaeration line, stand pipe or coolant return line flows. The insulated portion of the probe should be inserted into the coolant 0.5 in. or more past the inside wall of the tank. See Figure 3-33.
Determine proper location for low coolant level sensor while running the drawdown test. It must actuate a warning before the satisfactory drawdown level is reached.
The CLS components are OEM-supplied hardware and can be purchased as kits or individual components, depending on OEM requirements.
The following kits listed in Table 3-7 and listed in Table 3-8 provide all the necessary hardware for proper installation of the CLS. Kits are available through the DDC parts distribution network.
