G3500 Industrial Engines Caterpillar

The Timing Control Module (TCM) has these two programmable parameters: the desired timing and the speed timing map. The parameters affect the performance of the ignition system.

The parameters for the original TCM are set at the factory according to the engine application. The programmed values are stored in the TCM. If the TCM is replaced, the speed timing map and the desired timing must be programmed into the new TCM. The TCM must also be calibrated with the magneto when the TCM is replaced, or whenever the magneto is moved or replaced.

The parameters can be changed with the DDT. The parameters allow the operator to modify the ignition system for the proper application. The operator should be familiar with the effects of each parameter. Incorrect programming of the parameters may lead to problems with power and/or performance.

Note: The speed timing map can only be changed when the engine is stopped. If you attempt to change the map during engine operation, an "E4" diagnostic will be generated on the DDT. This diagnostic will not cause the engine to shutdown. Press the "CLEAR" key on the DDT in order to return to normal display operation.

Note: For details on using the DDT, see Special Instruction, SEHS8806, "Servicing the 3500 Spark Ignited Timing Control (Standalone Configuration)".

Use the following procedure to program a new TCM.

1. Connect the DDT to the TCM. Refer to Troubleshooting, "Connecting the DDT to the TCM".

Note: For information on navigating through the screens of the DDT, see Troubleshooting, "DDT Menu Map".

2. Use the DDT to access the menu for customer specified parameters (menu 03). Use screen 30 on menu 03 of the DDT in order to read the speed timing map from the old TCM. Record the map that is selected and record the corresponding maximum rated speed.

Show/hide table

There is a strong electrical shock hazard unless the system power is disconnected. Remove power from the control system. Turn the engine control switch to the "OFF/RESET" position. Open the circuit breaker in the engine mounted junction box.

3. Remove power from the control system. Turn the engine control switch to the "OFF/RESET" position. Open the circuit breaker in the engine mounted junction box.

4. Disconnect the old TCM from the engine harness and remove the old TCM.

5. Install the new TCM and connect the new TCM to the engine harness.

6. Restore power to the control system. Close the circuit breaker in the engine mounted junction box. Turn the engine control switch to the "STOP" position.

7. Use the DDT to access the menu for customer specified parameters (menu 03). Use screen 30 on menu 03 of the DDT in order to program the value for the speed timing map. Use the value from Step 2.

8. Use the DDT to access the menu for desired timing (menu 05). Use screen 50 on menu 05 of the DDT in order to program the desired timing.

   The desired timing must be programmed in three digits to one-tenth of a degree. For example, in order to program a desired timing of 28.0 degrees, press "<ALT1> 280 <ENTER>".

9. Calibrate the TCM with the magneto. Refer to Troubleshooting, "Magneto Calibration".