Freightliner Cascadia / Detroit DD13, DD15, DD16 & Cummins ISX etc. FAQs

Worn or damaged oil pump: If the oil pump is not functioning properly, it may not be able to generate enough pressure to circulate the oil properly. This can be fixed by replacing the oil pump. This along with the oil pick up tube o-rings that connect the oil pump to the suction manifold are both common issues on the DD series engines. Clogged oil filter: If the oil filter is clogged, it can restrict the flow of oil and cause low pressure. This can be fixed by replacing the oil filter. Low oil level: If the engine oil level is too low, it can cause low pressure. This can be fixed by adding more oil to the engine. Worn bearings: If the bearings in the engine are worn, they may not be able to properly support the moving parts of the engine, which can cause low oil pressure. This can be fixed by replacing the worn bearings. Worn or damaged oil pressure sensor: If the oil pressure sensor is not functioning properly, it may not be able to accurately measure the oil pressure. This can be fixed by replacing the sensor. Worn or damaged oil pick-up tube o-rings: The o-rings that connect the oil suction manifold to the oil pump can become worn or damaged over time, which can cause low oil pressure. Replacing the o-rings is usually the best way to fix this problem. These o-rings along with the oil pump are both common issues on the DD series engines. Other issues: There are a number of other potential causes of low oil pressure on a Detroit DD15 engine, such as a leak in the oil system, a faulty oil pressure gauge, or a problem with the oil pressure relief valve. These issues may require more specialized repairs.

Step 1: Check for fault codes related to the DPF pressure sensor. Use a diagnostic scan tool to retrieve fault codes related to the DPF pressure sensor. Determine if the sensor is causing the issue by checking for codes related to the DPF pressure sensor. Step 2: Perform a forced regeneration and monitor the parameters throughout the process. It may first be necessary to clear the fault codes first if the scan tool allows. During the regeneration process, be sure to monitor the temperatures, pressures, flow rates, etc. If the regeneration does not complete successfully or the parameters are not correct, it may be an indication of a problem with the DPF pressure sensor or another component of the emission control system. Step 3: Check/test the DPF pressure sensor. Inspect the sensor for any signs of damage or debris. Cracks and leaking components of the sensor are common due to the extreme heat on the plastic sensor. Also check the DPF pressure sensor tubes for soot build up, this is very common and causes the same issues. To clean you can just blow the tubes through with air, scrub them with a cylindrical brush or flush with a degreaser / solvent. Note that just because the sensor looks fine does not mean internally it is fine. Refer to manufacturer specifications to test the DPF pressure sensor to determine if it puts out the correct resistance across the pins etc. Replace the sensor if needed. Step 4: Check the wiring and connectors for the DPF pressure sensor. Inspect the wiring and connectors for any signs of damage, melting or corrosion. Repair or replace the wiring and connectors as needed. Refer to the manufacturer specifications for a pin out diagram to check voltage, resistance etc. Step 5: Check for issues with the exhaust system. Inspect the exhaust system for any issues, such as leaks or blockages. This can change the pressure in the system and blame it on the DPF pressure sensor Repair or replace any faulty components as needed. Step 6: Check for issues with the DPF or DOC. Probably the most expensive solution, but unfortunately if you’re seeing this code, are required to regen very often (like everyday) along with other codes, it may be best to get your DPF or DOC (diesel oxidation catalyst) inspected. If the DPF or DOC pass inspection you may just need to get the filters cleaned to remove the excess “ash” or soot. If you suspect that there may be an issue with the DPF, have the vehicle inspected by a professional. Have any faulty components repaired or replaced as needed.

Common Causes of DEF Contamination There are several common causes of DEF contamination in a Freightliner Cascadia with a Detroit DD15 engine. Here are a few: Mixing DEF with other fluids: DEF should never be mixed with other fluids, as it can cause contamination. Using incorrect concentration, low-quality or expired DEF: Using DEF that has an incorrect ratio of water to urea, is past its expiration date or of poor quality can lead to contamination. Dirty DEF pumps at a fill station: If you fill up your DEF from a station, watch out for dirty nozzles that can transfer debris to the inside of your DEF tank. Contaminated DEF storage containers: If the DEF is stored in containers that are not clean or are contaminated with other fluids, it can lead to contamination. DEF pump issues: If the DEF pump is not functioning properly, it can lead to contamination of the DEF. DEF filter issues: If the DEF filter is old, dirty, or plugged up, it can cause contamination of the DEF.