2005/01/10 Caterpillar

Articulated Truck:

725 (S/N: AFX1-UP)

730 (S/N: AGF1-UP)

735 (S/N: AWR1-UP)

740 (S/N: AXM1-UP)

740 EJECTOR (S/N: AZZ1-UP)

Service Magazine, SEPD0766, 01 2005, "New Engine Software Improves Reliability of the Air Filter Restriction System on Articulated Trucks". Disregard this article. See the replacement article that follows.

Description of Change: New engine software is now used in order to improve sensor reliability on Articulated Trucks. This software provides new sensor calibrations and warning debounce times.

New Settings for E272 Air Filter Restriction:

The software will provide automatic calibration of the turbo inlet pressure sensor to atmospheric sensor in order to reduce errors in the air filter restriction measurement.

The Electronic Control Module (ECM) detects an E272 if the following condition is present:

• The inlet air restriction reaches 7.5 kPa for longer than 30 seconds.

The new engine software has also been improved to reduce the number of false "Low Engine Oil Pressure" warnings. This improvement extends the time that pressure must be low from 2 seconds to 8 seconds.

New Setting for E100 Low Oil Pressure Warnings: (3176C and 3196 Engines)

The Electronic Control Module (ECM) detects an E100 if all of the following conditions are present:

• Engine Oil Pressure is in the "Low Oil Pressure Region" in Illustration 1 for 8 seconds.

• The engine has been running for at least 10 seconds.

Illustration 1	g01124867

New Setting for E100 Low Oil Pressure Warnings: (3406E and 3456 Engines)

The Electronic Control Module (ECM) detects an E100 if all of the following conditions are present:

• Engine oil pressure is in the "Low Oil Pressure Region" in Illustration 2 for 8 seconds.

• The engine has been running for at least 10 seconds.

Illustration 2	g01124869

Adaptable To: This change is adaptable to the serial numbers that are found in Table 1.

Table 1

Sales Model	New Software Part Number	Previous Software Part Number	Serial Number
725	256-8797	220-0127	AFX 00001-1097
	257-5796	251-7234	AFX 01098-UP
730	256-8798	220-0128	AGF 00001-1010
	257-5797	251-7235	AGF 01011-UP
735	256-8799	220-0129	AWR 00001-624
	257-5798	254-1473	AWR 00625-UP
740	256-8800	220-0130	AXM 00001-1376
	257-5799	246-4699	AXM 01377-UP
740EJ	256-8800	220-0130	AZZ 00001-339
	257-5799	246-4699	AZZ 00340-UP

This change is effective with the serial numbers that are found in Table 2.

Table 2

Sales Model	Serial Number
725	S/N: B1L 00001-UP
730	S/N: B1M 00001-UP
735	S/N: B1W 00001-UP
740	S/N: B1P 00001-UP
740EJ	S/N: B1R 00001-UP