Exhaust Temperature Module Caterpillar

Illustration 1	g01223384
251-9430 Exhaust Temperature Module

The 251-9430 Exhaust Temperature Module (ETM) is an engine exhaust temperature scanner. The scanner is able to check up to 24 points via standard type K thermocouples. An LCD displays the number of the channel and the temperature in °C or in °F. The scanner has two output switches. The switches can be configured as either a normally open switch or a normally closed switch. The factory default setting for both switches is normally open. The switches can be wired to alarms or to relays. The scanner can provide readings, monitoring, and alarms for the temperatures of 20 cylinder exhaust ports and four turbocharger inlets and/or outlets.

The ETM supports the SAE J1939 datalink and the RS-485 datalink. These datalinks allow the transmission of temperatures from the ETM to other components such as an EMCP 3.3, an Advisor Panel, or other supported J1939 devices. For more information in this manual, refer to Systems Operation, Testing and Adjusting, "Communication".

The scanner has a microprocessor for processing the input signals. The microprocessor has non-volatile memory for storing programmable parameters and other data. The user interface is a keypad. The following functions are among the uses of the keypad:

• Change the display of the temperatures to °C or to °F.

• Select automatic display or manual display for the scan.

• Display a history of channels which have exceeded the setpoints.

• Change the filter for the display in order to stabilize the readings for a signal that is fluctuating.

• Program the temperature setpoints.

• Lock the keypad in order to help prevent changing of the non-volatile memory.

• Calibrate the scanner.

The scanner can monitor temperatures from 0 to 850 °C (32 to 1562 °F). Six temperature setpoints for the alarms can be programmed with the keypad. If an alarm occurs, the scanner has two output switches that can provide a signal to an indicator, to a switch, or to a relay.

Note: If the engine is cleaned with water or with a cleaning solution, avoid a direct spray to the rear or sides of the ETM.