Series 50 – Section 2.19 Oil Temperature Sensor

Section 2.19
Oil Temperature Sensor

The Oil Temperature Sensor (OTS) is installed into the main engine oil gallery. A typical location is the left rear corner of the cylinder block. See Figure "Engine Oil Pressure and Temperature Sensors" . The OTS sends an electrical signal to the ECM indicating engine oil temperature. The ECM uses this information to modify engine speed for better cold weather starts and faster warm-ups. Oil temperatures exceeding specification for two seconds or more will begin the stop engine or warning function. ‪

Note: Series 50G automotive (high pressure fuel system) engines do not have an oil temperature sensor. All DDEC and OEM functions reference coolant temperature.

Figure 1. Engine Oil Pressure and Temperature Sensors

Section 2.19.1
Repair or Replacement of Oil Temperature Sensor

The OTS is non-serviceable, and is replaced as a unit. No adjustment is required.‪

Section 2.19.2
Removal of Oil Temperature Sensor

Removal the OTS as follows: ‪

1. Disengage the locking tang on the two-wire connector.
2. Grasp the body of the connector and gently pull it from the socket.
3. Use the appropriate wrench on the hex portion of the sensor and unscrew it.

Section 2.19.3
Installation of Oil Temperature Sensor

Install the OTS as follows: ‪

Note: The Oil Temperature Sensor is an electronic device. Use care in the installation process.

1. Place the sensor and using the appropriate wrench on the hex portion of the sensor tighten the screws.
2. Use Loctite Pipe Sealer with Teflon, J 26558-92 part of PT-7276 (or equivalent) on all but the first two threads of the OTS to prevent leaks.
3. Place the connector in the socket and engage the locking tang.
4. 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.