DEF Tank

This procedure addresses a common confusion: 1994-2007 Dodge Ram 2500 Cummins diesel trucks do not have DEF (Diesel Exhaust Fluid) tanks, as DEF systems were not introduced until 2010 with EPA emissions regulations.

Warnings

Tools required

Preparation

1. Verify the actual model year of your vehicle - check the VIN plate on the driver door jamb
2. Confirm engine type by visual inspection - the 5.9L Cummins should have NO DEF tank, NO blue DEF filler cap, and NO selective catalytic reduction (SCR) system
3. If you have a 2010 or newer Ram with a 6.7L Cummins, refer to the appropriate repair procedure for that model year
4. Review the emission control label under the hood to identify what emissions equipment is present on your specific vehicle

Procedure

1. 1

   Verify Vehicle Identification
   Locate the VIN (Vehicle Identification Number) on the driver side door jamb or dashboard. The 10th digit indicates model year: R=1994, S=1995, T=1996, V=1997, W=1998, X=1999, Y=2000, 1=2001, 2=2002, 3=2003, 4=2004, 5=2005, 6=2006, 7=2007. None of these model years have DEF systems.
2. 2

   Inspect Exhaust System Configuration
   Raise vehicle safely on a lift or jack stands. Inspect the exhaust system from the turbo outlet to the tailpipe. 1994-2007 models have a simple exhaust manifold, turbocharger, downpipe, and muffler system with NO DPF (diesel particulate filter) canister and NO SCR catalyst.
3. 3

   Check for Aftermarket DEF System
   In rare cases, an aftermarket DEF/SCR system may have been installed for specific commercial or agricultural applications. Inspect the driver side frame rail near the fuel tank for any non-factory tanks or blue filler caps. Check for aftermarket wiring harnesses or control modules mounted near the firewall.
4. 4

   Identify Actual Problem
   If you were directed to service a DEF tank due to a warning light, check engine light, or performance issue, the actual problem is NOT DEF-related. Common issues mistaken for DEF problems include: lift pump failure, VP44 injection pump issues (1998.5-2002), injector problems, turbo boost leaks, or or injector/common-rail fuel system problems (2003-2007 models).
5. 5

   Review Emissions Equipment Present
   1994-1997.5 models (12-valve) have NO electronic emissions controls. 1998.5-2002 models (24-valve VP44) have minimal emissions controls. 2003-2007 models (24-valve common-rail) added electronic engine controls but still have NO EGR system. NONE have EGR, DPF, DEF, or SCR systems.

Reassembly

1. No reassembly required - this is a verification procedure only
2. If an aftermarket DEF system was found and requires service, consult the aftermarket manufacturer's documentation
3. Lower vehicle from lift or jack stands once inspection is complete

Verification

• Confirm vehicle model year is 1994-2007 and does not require DEF service
• Identify the actual maintenance or repair need based on symptoms observed
• Refer to appropriate repair procedures for the actual problem (fuel system, turbo, EGR, etc.)
• If working on a 2010+ model, obtain the correct DEF tank replacement procedure for that generation

More procedures for this vehicle