Series 50 – Section 2.22 Coolant Level Sensor

Section 2.22
Coolant Level Sensor

The Coolant Level Sensor (CLS) is a two-piece sensor. See Figure "Two-piece Coolant Level Sensor (CLS)" . The sensor probe (supplied by the vehicle manufacturer) is mounted in the top tank or overfill tank. The sensor module is mounted on the vehicle. The module sends an electrical signal to the ECM to indicate coolant level. Low coolant will activate the stop engine function or warning function. ‪

Figure 1. Two-piece Coolant Level Sensor (CLS)

Section 2.22.1
Repair or Replacement of Cooling Reference Sensor

Both the CLS probe and module are non-serviceable and should be replaced as necessary.‪

Section 2.22.2
Removal of Cooling Reference Sensor

Remove the CLS as follows:‪

1. Open the drain cock at the bottom of the radiator and drain the coolant into an appropriate container. Remove only as much coolant as is necessary to clear the CLS probe.
2. Remove ground wire screw and ground wire from side of probe. Loosen and remove nut from sensor lead of probe. Remove sensor lead, or unplug the two-pin connector.
3. Use the appropriate wrench on the hex portion of the sensor and unscrew it from the radiator.

Section 2.22.3
Installation of Cooling Reference Sensor

Install the CLS probe as follows:‪

1. Use the appropriate wrench on the hex portion of the sensor and screw it into the radiator.
2. Install ground wire screw and ground wire from side of probe. Install and tighten nut from sensor lead of probe. Install sensor lead, or unplug the two-pin connector.
3. Close the drain cock at the bottom of the radiator.
4. Refer to "4 Cooling System" and fill the cooling system.
5. Turn the ignition to the "ON" position. Observe or read any diagnostic codes. If any code other than 25 appears, refer to the DDEC II  Troubleshooting Guide, 6SE489, or DDEC  III/IV Single ECM Troubleshooting Guide, 6SE497.

   PERSONAL INJURY ‪
   Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪ Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system.

6. Start the engine and check for leaks.

Section 2.22.4
Removal of Cooling Reference Sensor Module

Remove the CLS module as follows:‪

1. Disengage the locking tang on the CLS module connector. Grasp the connector bodies and gently pull them apart.
2. Remove module from vehicle.

Section 2.22.5
Installation of Cooling Reference Sensor Module

Install the CLS module as follows:‪

Note: The CLS module is an electronic component. Use care when installing.

1. Insert the CLS module to the vehicle.
2. Engage locking tang on CLS module connector.