C-12 Generator Set Engine Caterpillar

The Electronic Control Module (ECM) has the ability to calibrate the mechanical differences between the Top Center (TC) of the flywheel and the TC of the timing gear on the camshaft. A magnetic transducer signals the TC of the flywheel to the ECM when a notch on a counterweight passes by the transducer. The engine speed/timing sensor signals the TC of the timing gear to the ECM. Any offset between the TC of the flywheel and the TC of the timing gear is stored into the memory of the ECM.

Note: A timing calibration will not increase the available engine power.

Table 1 lists the special tools that are required in order to perform this procedure.

Test Step 1. Install the Transducer Adapter

1. Remove electrical power from the engine ECM.

2. Use the appropriate engine turning tool to put either the No. 1 piston or the No. 6 piston at top center.

3. After the top center position has been located, rotate the crankshaft in the opposite direction of normal rotation for 60 degrees.

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Illustration 1	g01154177
C12 right side view (typical example) (1) Plug

4. Refer to Illustration 1. Locate the engine's timing calibration port on the number 8 crankshaft counterweight on the right side of the engine.

5. Remove plug (1) from the timing calibration port.

6. Thread the transducer adapter into the port.

Results:

Continue to the next test step.

Test Step 2. Install the Transducer

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NOTICE
If the crankshaft is not in the correct position when the transducer is installed, the transducer will be damaged when the engine is started.

1. Apply clean engine oil to a 2D-6392 O-Ring Seal. Install the O-ring seal on the end of the 6V-2197 Transducer .

2. Push the transducer through the transducer adapter until the transducer contacts the crankshaft counterweight.

3. Withdraw the transducer 1.0 mm (0.04 inch) and hand tighten the nut on the adapter sleeve in order to secure the transducer. Move the O-ring seal against the adapter.

Results:

Continue to the next test step.

Test Step 3. Connect the 7X-1695 Cable As

1. If the engine harness is equipped with a connector for timing calibration, connect the 7X-1695 Cable As to the connector for timing calibration and to the transducer.

2. If the engine harness is not equipped with a connector for timing calibration, perform the following procedure:

   1. Disconnect the P2 connector from the ECM.

   2. Remove the sealing plugs from P2-22 and P2-23. Do not discard the sealing plugs. The sealing plugs may be reinstalled when the timing calibration is complete.

   Note: Ensure that each wire is installed into the correct location. The timing calibration will not be successful if the wires are installed incorrectly.

   3. Install the white wire of the 170-3519 Harness into P2-22.

   4. Install the yellow wire of the 170-3519 Harness into P2-23.

   5. Connect the J2/P2 connectors. Tighten the allen head screw on the P2 connector to the appropriate torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.

   6. Connect the 7X-1695 Cable As to the connector for timing calibration and to the transducer.

Results:

Continue to the next test step.

Test Step 4. Start the Engine and Check for Diagnostic Codes

1. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".

2. Start the engine and run the engine until the engine is at the normal operating temperature.

3. Check for active diagnostic codes.

   The engine must not have any active diagnostic codes during the timing calibration except for a 261-13 Engine Timing Calibration required.

Expected Result:

There are no active diagnostic codes or there is only an active 261-13 diagnostic code.

Results:

• OK - There are no active diagnostic codes or there is only an active 261-13 diagnostic code. Proceed to Test Step 5.

• Not OK - There is at least one active code that is not 261-13.

  Repair: Troubleshoot and repair any active diagnostic codes before you continue with this procedure.

  STOP

Test Step 5. Calibrate the Engine Speed/Timing Sensor

1. Set the engine speed to 1100 ± 50 rpm. The engine speed must be steady within this rpm range in order for the calibration to be successful.

2. After the engine has warmed up, access the "Timing Calibration" screen on the Cat ET. Access the following display screens in order:
   • Service

   • Calibrations

   • Timing Calibration

3. To calibrate the timing, select "Continue" on Cat ET. Wait until Cat ET indicates that the timing is calibrated.

Expected Result:

Cat ET indicates that the timing is calibrated.

Results:

• OK - Cat ET indicates that the timing is calibrated.

  Repair: Perform the following procedure:

  1. Set the engine speed to low idle.

  Note: Disconnect the 7X-1695 Cable As before you exit the "Timing Calibration" screen. Otherwise, diagnostic codes may be activated.

  2. Disconnect the 7X-1695 Cable As .

  3. Exit the "Timing Calibration" screen on Cat ET.

  4. Turn the keyswitch to the OFF position.

  5. Remove the transducer and remove the adapter.

  6. Install the plug into the timing calibration port.

  7. If you installed a 170-3519 Harness, you may remove the harness or you may permanently install the harness for future use. If you remove the harness, install the sealing plugs into the unused cavities of the P2 connector. Otherwise, moisture and debris will enter the connector.

     If you choose to permanently install the harness, fasten the harness to the existing engine wiring harness with cable ties. Also, install a 3E-3364 Receptacle and two 8T-8737 Seal Plugs on the P400 timing calibration probe connector in order to prevent moisture and debris from entering the connector.

  8. Return the engine to service.

  STOP

• Not OK - The timing calibration was unsuccessful.

  Repair: The following conditions can cause the timing calibration to fail:

  • If the crankshaft and camshaft gears have been reassembled incorrectly, the timing will not calibrate.

  • Verify that the timing calibration probe is installed correctly.

  • Verify that the engine speed is correct and that the engine speed is stable. If the engine speed is unstable, refer to Troubleshooting, "Engine Misfires, Runs Rough or Is Unstable".

  • There may be a problem with the transducer or with the cables. Obtain a new transducer and/or a new cable and repeat the timing calibration.

  STOP