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The Timing Reference Sensor (TRS) is an electronic component that is mounted to the left side of the gear case, near the crankshaft centerline. See Figure 20274 . ‪

Timing Reference Sensor Location

Note: The length of the TRS sensor element is 56.06-56.58 mm (2.207-2.227 in.).

The sensor portion of the TRS extends through an opening in the gear case, and is positioned near the teeth of the timing wheel. A bolt, inserted through a hole in the TRS bracket, secures the TRS assembly to the gear case. The TRS connector is gray in color. ‪

The TRS sends a signal to the ECM. This signal is generated by a series of evenly spaced teeth on the timing wheel. As the timing wheel rotates with the crankshaft, a tooth passes by the TRS. These signals are used by the ECM to determine injector solenoid operation times and engine speed. ‪

Replacement of Timing Reference Sensor

The TRS is a non-serviceable component and is replaced as a unit. No adjustment is required. ‪

Removal of Timing Reference Sensor

Remove the TRS as follows: ‪

  1. Disengage the locking tang on the TRS connector. Grasp the connector bodies and gently pull them apart.
  2. Remove the bolt that secures the TRS to the gear case.
  3. Remove the TRS by pulling it straight out of the gear case.

Installation of Timing Reference Sensor

Install the TRS as follows: ‪

Note: The TRS is an electronic component. Use care upon installation.

  1. The O-ring on the sensor may be coated with clean engine oil for ease of installation.
  2. Insert the TRS into the gear case and index the hole in the bracket with the hole in the gear case.
  3. Insert the TRS bolt and torque it to 30-38 Nm (22-28 lbft).
  4. Plug the connectors together, making sure the locking tang clicks into place.
  5. Turn the ignition to the ON position. Observe or read any diagnostic code(s). If any code other than code 25 appears, refer to the required DDEC Troubleshooting Manual: 6SE477 (DDEC I), 6SE489 (DDEC II), or 6SE497 (DDEC III/IV).