Challenger 35, Challenger 45 and Challenger 55 Agricultural Tractors Electronic Systems Caterpillar

Description

In this mode the technician can check the inputs (switches, potentiometer and sensors) to all modules without using additional testing equipment. When the technician operates any switch, sensor or potentiometer, the display area of the MPM will identify the input and indicate if the input is functioning. All inputs are assigned a unique four digit parameter ID number (P_ _ _ ). For a list of all the Mode 3 parameter ID numbers, see the table "Mode 3 Parameter Identification".

When a switch or sensor is activated or deactivated (changes state) the following happens:

• The alarm horn will emit an audible tone to indicate the switch and circuit are working.

• A unique four digit parameter ID number (P_ _ _ ) that corresponds to the input being tested will automatically be shown on the readout (1).

• The actual status of the input is shown on the readout (19). "Hi" means the voltage is high at the module input. Such as in a closed or working circuit switched to +12V. A pulsating audible tone will sound when "Hi" is shown. "Lo" means the sensor voltage is low at the module input. Such as in an open switch. A single audible tone will sound. For potentiometers, a two digit value "_ _" (0 to 99) is shown to indicate the percent of full scale.

• When the sensor or switch is returned to its original position, the alarm horn will emit a different tone.

Note: A specific parameter ID number (P _ _ _ ) can also be selected by the technician to be shown on the readout (1). See the following procedure.

Note: If no change is noticed when a circuit is activated, an input fault is present. Troubleshoot that half of the circuit.

Note: Ensure that all potentiometers have a smooth transition of digits throughout the range of values.

Examples

Illustration 1	g00566476
Display shows that the downshift switch has been activated and is at +12V. (1) Readout (2) Digit Set key (3) Digit Select key (4) "Setup/Select" key (5) "Start/Stop/Reset" key (6) "Exit/Mode" key (19) Readout

After Mode 3 is entered and the shift control lever is moved to the left (downshift), the technician should observe the following conditions:

• The alarm horn will emit an audible tone. This means an input has changed state.

• Readout (1) will show "P109". This identifies the downshift input as the input that has changed state.

• Readout (19) will show "Hi". This means the voltage at the downshift input of the module is +12 volts (Hi).

Illustration 2	g00566481
Display shows that the draft sensitivity potentiometer has been turned and is 64% of full scale. (1) Readout (2) Digit Set key (3) Digit Select key (4) "Setup/Select" key (5) "Start/Stop/Reset" key (6) "Exit/Mode" key (19) Readout

After Mode 3 is entered and the draft sensitivity knob (potentiometer) is turned, the technician should observe the following conditions:

• The alarm horn will emit an audible tone. This means an input has changed state.

• Readout (1) will show "P121". This identifies the draft sensitivity input as the input that has changed state.

• Readout (19) will show a two digit value, for example "64". This means the potentiometer (in the present position) is at 64% of full scale.

Procedure to Use Mode 3

Illustration 3	g00566485
All Module Input Diagnostic Illustration. (1) Readout (2) Digit Set key (3) Digit Select key (4) "Setup/Select" key (5) "Start/Stop/Reset" key (6) "Exit/Mode" key (19) Readout

1. Enter the All Module Input Diagnostic Mode (Mode 3):

   1. Turn key start switch from OFF to ON.

   2. Press and hold the "Setup/Select" key (4) for three seconds.

   3. Press the digit set key (2) until the readout (1) shows "_ _ _ 3".

   4. Press and hold the "Setup/Select" key (4) for three seconds in order to enter Mode 3. Readout (1) will show the parameter identifier that was viewed when Mode 3 was last exited.

2. The technician can now test the following components for functionality: switches, sensors and potentiometers. The EMC will operate as described in the preceding Description Section.

3. To check a specific input, determine the desired parameter ID number. See the table for "Mode 3 Parameter Identification".

4. Press the "Setup/Select" key (4). Readout (1) will show "P000" with the first "0" flashing.

5. Enter the desired parameter ID number on the readout (1). The value of each digit is changed one at a time. The flashing digit identifies the digit to be changed. Pressing digit set key (2) increases the numerical value of the flashing digit. Pressing the digit select key (3) causes the next digit to flash and it can now be set by using digit set key (2).

6. With the desired parameter ID number showing on readout (1), activate the circuit and the EMC will operate as described in the preceding Description Section. No other switches, senders or potentiometers will change the display while a specific parameter ID number is selected.

7. To re-select the automatic parameter selection, press "Setup/Select" key (4). To return to the single parameter selection, again press "Setup/Select" key (4). Pressing "Setup/Select" key (4) toggles the operation back and forth between automatic and single parameter selection.

8. To return the EMC to the Service Mode selection, press "Exit/Mode" key (6) one time. To return the EMC to normal operation, press "Exit/Mode" key (6) two times.