Contaminants-in-Diesel Exhaust Fluid Diagnosis

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 4976125 Description Maximum oxides of nitrogen (NOx) reduction efficiency of the selective catalyst reduction system requires the supply of diesel exhaust fluid (reductant). Consisting of a mixture of urea and deionized water, fresh reductant should be clear in color with an ammonia smell. Reductant designed for selective catalyst reduction systems should carry one or more of the following international certifications: DIN70700 ISO 22241-1 American Petroleum Institute (API) Certification Inspecting for Contaminates While contamination may result from any number of fluids, it’s more likely that contamination will involve one the following common automotive fluids. As clean reductant is clear, contamination by any of these fluids will cause the reductant to exhibit a trace of color associated with a specific contaminate. Windshield washer solvent – orange, purple or blue Engine coolant – orange or green Engine oil – brown Transmission fluid – red or brown Diesel fuel – clear, yellow, green, red or brown Clear fluid without the presence of an ammonia odor may indicate water or reductant diluted with water. Reference Information Scan Tool Reference Control Module References for scan tool information Special Tools J 26568 Coolant and Battery Fluid Tester OR EN 50422 Diesel Exhaust Fluid Refractometer Circuit/System Testing

Warning

Diesel Exhaust Fluid (DEF) is corrosive. Do not allow it to come in contact with your skin, eyes, or the finished surfaces of the vehicle. If exposed, it may cause skin and eye irritation. Wear skin and eye protection when handling. Inhalation may cause irritation to the upper respiratory tract. Store in a cool, well-ventilated area. For more safety information, see the label of the Diesel Exhaust Fluid container. Failure to follow this procedure may result in injury and/or vehicle damage.

1. Test a sample of reductant by collecting about 150 ml (5 oz) from the reductant tank in a clear container. Observe the reductant sample. The reductant sample should have an ammonia smell and should be clear with no obvious coloration when held up to a light. ⇒ If the sample does not have an ammonia smell or is discolored 1.1. If the sample is contaminated with engine coolant or windshield washer solvent, flush the reductant system.

Note

If the engine was never started and the sample is contaminated with diesel fuel, engine oil, transmission oil, or other petroleum-based product, only replace the emission reduction fluid tank and flush the emission reduction fluid tank opening filler. 1.2. If the engine has been started and the sample is contaminated with diesel fuel, engine oil, transmission oil, or other petroleum-based product, flush the emission reduction fluid tank opening filler with fresh reductant, and replace the following components: Emission reduction fluid tank Emission reduction fluid reservoir assembly A38 Emission Reduction Fluid Pump Module Q61 Emission Reduction Fluid Injector Emission reduction fluid reduction injector supply pipe ⇓ If the sample has an ammonia smell and is not discolored

2. Test the reductant sample using one of the tools listed below: J 26568 OR EN 50422
3. Verify the sample is within the range specified below: J 26568– Between 1.310 and 1.3843 at 20°C (68°F) EN 50422– Between 30% and 35%. ⇒ If not within the specified range Drain the remaining reductant and refill the tank with fresh reductant ⇓ If within the specified range
4. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification