Series 638 – Section 2.7 Coolant Temperature Sensor (ECM)

Section 2.7
Coolant Temperature Sensor (ECM)

The CTS is required for the Turbotronic 638. It provides input to the engine protection system. The CTS is also used to determine engine operating temperature for fuel delivery.‪

The main component of the CTS consists of a conductivity probe which connects the ECM.‪

Section 2.7.1
Replacement of Coolant Temperature Sensor (ECM)

To determine if replacement of the coolant temperature sensor (ECM) is necessary, perform the following procedure. See Figure "Flowchart for Replacement of Coolant Temperature Sensor (ECM)" .‪

Note: The CTS is non-serviceable and should be replaced as necessary.

Figure 1. Flowchart for Replacement of Coolant Temperature Sensor (ECM)

Section 2.7.2
Removal of Coolant Temperature Sensor (ECM)

Remove the coolant temperature sensor as follows:‪

1. Drain the cooling system. Refer to "13.4.5 Cooling System" .
2. Disconnect the coolant temperature sensor wire harness. See Figure "Coolant Temperature Sensor and Wire Harness Removal" .
   

   1.Coolant Temperature Sensor‪

   2.Number 2 Cylinder Head‪

   Figure 2. Coolant Temperature Sensor and Wire Harness Removal

3. Remove the coolant temperature sensor. See Figure "Coolant Temperature Sensor and Wire Harness Removal" .

Section 2.7.2.1
Inspection of Coolant Temperature Sensor (ECM)

Inspect the coolant temperature sensor as follows:‪

1. Visually check the coolant temperature sensor for corrosion or rust.
   1. If the coolant temperature sensor has corrosion or rust, clean as necessary. Refer to "2.7.3 Installation of Coolant Temperature Sensor (ECM)" .
   2. If the coolant temperature sensor has no corrosion or rust, proceed with step 2 of inspection.
2. Visually check the coolant temperature sensor for bent, broken, or missing pins.
   1. If the coolant temperature sensor has bent, broken, or missing pins, replace the component. Refer to "2.7.3 Installation of Coolant Temperature Sensor (ECM)" .
   2. If the coolant temperature sensor has no bent, broken, or missing pins, reuse the component. Refer to "2.7.3 Installation of Coolant Temperature Sensor (ECM)" .

Section 2.7.3
Installation of Coolant Temperature Sensor (ECM)

Install the coolant temperature sensor as follows:‪

1. Install the coolant temperature sensor. Torque to 13 N · m (10 lb · ft). See Figure "Coolant Temperature Sensor Installation" .
   

   1.Coolant Temperature Sensor‪

   2.Number 2 Cylinder Head‪

   Figure 3. Coolant Temperature Sensor Installation

2. Reconnect the coolant temperature sensor wire harness.
3. Fill the coolant system. Refer to "13.4.5 Cooling System" .
4. Run the engine to verify repair.