2004.5-2007 Dodge 5.9L Cummins Gauges & Monitors

Digital monitors on the 2004.5-2007 RAM 5.9L Cummins

The factory gauges on these third-generation Dodge Rams leave out three readings the common-rail owners' literature tells you to watch: boost, exhaust gas temperature and fuel pressure. An aftermarket digital monitor fills that gap. It plugs into the OBD-II port and reads rail pressure, boost and coolant temperature straight from the ECM of the 5.9L Cummins. Two readings the ECM cannot give you need add-on sensors: EGT, from a pyrometer probe in the exhaust manifold ahead of the turbo, and lift-pump pressure, from an electric sender on the low-pressure fuel side.

What a monitor helps you catch

The monitors themselves do not have a known failure pattern on this truck. What they do is warn you before the engine develops one.

• High EGT. The guidance for 2004.5-2007 engines is a 1,500 F ceiling. A truck making more fuel than stock on the factory Holset HE351CW can push past it, especially towing or at altitude. After repeated excursions, the first thing that usually lets go is a dropped valve seat, which shows up as a sudden miss or knock. TDR guidance is to keep EGT under about 1,300 F on long pulls.
• Low lift-pump pressure. Pressure falling below about 5 psi at full power is the early warning for CP3 starvation and injector damage. Without a gauge, the first symptom is usually a hard start, a long crank or a P0087 low rail pressure code. Lift-pump life on the 24-valve runs about 100,000 miles.
• Rail pressure at crank. A healthy truck usually shows 4,300-5,800 psi during crank, before it starts, and Chrysler lists the operating range as 4,321-23,206 psi. A monitor that reads rail pressure lets you check that yourself when the truck starts hard.

Choosing a setup

Start with how you use the truck. If you tow, the EGT reading is the one you will watch most. If you run an aftermarket electric lift pump, a fuel-pressure gauge is the recommended companion, and TDR advice is to keep an eye on that pressure and carry a spare pump. The complete setup the TDR guidance describes is an OBD-II monitor with an EGT probe in the manifold ahead of the turbo and an electric fuel-pressure sender. Use an electric sender rather than routing diesel into the cab, and mount it remotely with a snubber. If you add power, stick to CARB EO-numbered products and verify each one for your model year.

What we carry

• Edge Products 98620 EAS EGT kit, the Daily Driver/Tow kit, for adding an exhaust gas temperature reading.
• Edge Products 98607 EAS pressure sensor, rated 0-100 psi.
• Edge Products 38600 A-pillar display mount.

The EGT kit and pressure sensor are part of Edge's EAS accessory line. Check each product page for the Edge displays they work with.

Fitment notes

Ram and Cummins moved to a CAN-bus capable ECM for the 2006 model year, and that change affects monitor and tuner compatibility, so check each monitor's own fitment list against your year. The lift pump also moved: 2004.5 trucks, which are 2004 model year, have it on the engine, and 2005-2007 trucks have it in the tank. Check where yours is before you plan a fuel-pressure sender. The A-pillar mount is listed for 2006-2009 trucks, which lines up with the interior that came with the 2006 refresh, so 2004.5-2005 owners should confirm fit first. And because the 2007 model year includes 6.7L trucks built after January 1, 2007, confirm your engine. ST, SLT or Laramie, verify by VIN.

Frequently asked questions

Does the 2004.5-2007 Ram have a factory boost or EGT gauge?

No. These trucks have no factory boost, EGT or fuel-pressure readout. An OBD-II monitor can show boost and rail pressure from the ECM, but EGT needs a pyrometer probe and lift-pump pressure needs an electric sender.

Where does the EGT probe go?

In the exhaust manifold, ahead of the turbo. The guidance for 2004.5-2007 engines is a 1,500 F ceiling, and TDR advises staying under about 1,300 F on long pulls. If you tow, that is the number to keep in view.

What fuel pressure reading should worry me?

Lift-pump pressure falling below about 5 psi at full power is the early warning for CP3 starvation and injector damage. Without a gauge you may not know until the truck starts hard or sets P0087. The factory lift pump is a low-pressure pump of about 10 psi.

Will any monitor work on my 2004.5-2007 Ram?

Not necessarily. The 2006 model year brought a CAN-bus capable ECM, and that affects monitor and tuner compatibility. Check the monitor's fitment list against your exact year before ordering, and call us if it is unclear.

Can I run a mechanical fuel-pressure gauge in the cab?

Use an electric sender instead. It keeps diesel out of the cab. Mount the sender remotely with a snubber and run the signal to your display.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.