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Dodge Ram Diesel Engine Evolution
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Emission Components      Emission standards
1991 "Super B"       1994-98 "Killer B"          1998+ ISB engine
Much of the information on this page came from TDR issues

Emission components

NOx - oxides of nitrogen:

PM - particulate matter HC - hydrocarbons CO - carbon monoxide
EPA Mandated Diesel Emission standards 
 Year gm/bhp-hr
Pre 1988 10.7 1.3 --
1988 10.7 1.3 0.6
1990 6.0 1.3 0.6
1991 5.0 1.3 0.25
1994 5.0 1.3 0.1
1998 4.0 1.3 0.1

The 1991 "Super B" diesel

Improvements to meet Jan 1, 1991 EPA standards

Reducing the injector size and increasing injection pressure raises the combustion pressure which required 1992 1/2 engine changes

The 1994 "Killer B" diesel (begins January 1 1994)

1994 models built from July 1993 to January 1, 1994 DO NOT have catalytic converters.

Improvements to  meet Jan 1, 1994 EPA standards

1995 engine changes (begins July 1994) 1996 215 HP engine changes (begins July 1995) 1997 engine changes (begins July 1996)

The 1998 ISB diesel (begins January 1 1998)

ISB Improvements over the 12 Valve Cummins TurboDiesel
Information obtained from TDR issues and Chrysler Master Tech No 2  February 1998.

See Master Tech Issue 2 from Feb 1998 for more ISB details

1999 ISB engine changes (begins July 1998)

2000 ISB engine changes (begins July 1999)

2001 ISB engine changes (begins Jan 1, 2000)

2001.5 ISB engine changes (begins July, 2000)

1998-2002 ISB Engine Components Specific to Chrysler

Fuel Injection Pump – Chrysler ISB engines are equipped with the Bosch® VP44 fuel pump. The VP44 fuel pump used for Chrysler ratings has a unique fueling map to obtain higher governed speeds. The Chrysler ISB injection pump is not interchangeable with other ISB fuel pumps. The VP44 is an electronically controlled rotary distributor fuel pump and is controlled by the Cummins ECM.

Engine Mounted ECM – The Cummins ECM is mounted on the left side of the engine block below the fuel filter. The ECM controls the Bosch® VP44 fuel pump by issuing fueling commands based on engine speed, load, and accelerator position. It also monitors the sensors on the engine to be sure that it is operating properly. The ECM logs fault codes generated internally to the Cummins electronic system as well as fault codes generated by the Bosch® VP44 fuel pump.
This ECM is specific to the Dodge pickup application. It is equipped with a single 50–pin connector which allows it to connect to engine mounted sensors as well as to the trucks electronic system. For this reason, other ISB ECMs, engine harnesses, and calibrations cannot be installed on Dodge trucks.

Wiring Harness – The wiring harness has a 50–pin connector that is specific to the Dodge pickup application. It connects the engine-mounted sensors, as well as the Dodge chassis computer (JTEC), to the Cummins ECM.

Throttle Position Sensor (TPS) – The TPS assembly is engine mounted and is specific to the Chrysler ISB application. The TPS is calibrated by the manufacturer and is not field adjustable. This part is available through the Chrysler parts network.

Electronic Service Tools – INSITE™ Version 4.2 in conjunction with INLINE™2 datalink adapter will have the capability of communicating with the Chrysler ISB engine. The service tool connection can be found above the fuel pump and will be a 3–pin Deutsch plug connection. A 2–pin Weatherpack connection is also available for datalink power.


Last update March 4, 2000