Use INSITE’M electronic service tool to check for fault codes. If any fault codes are present, follow the
corresponding troubleshooting tree before performing any part of this procedure.
The fault code troubleshooting tree in some cases will refer back to this procedure to complete the diagnostics.
Exhaust System Outlet Inspection
• Inspection of the exhaust system outlet can reveal the condition of the aftertreatment diesel particulate filter.
The exhaust system outlet should appear clean with little to no exhaust residue/soot buildup.
• The aftertreatment diesel particulate filter is not 100 percent efficient. Some accumulation of exhaust residue/soot is normal and does not indicate a malfunctioning aftertreatment diesel particulate filter.
• A heavy buildup of exhaust residue/soot can indicate a malfunctioning aftertreatment diesel particulate filter.
To determine if the exhaust residue/soot accumulation on the exhaust system outlet is the result of a malfunctioning aftertreatment diesel particulate filter, perform one of the following :
• Snap Acceleration Test as outlined in this procedure.
• Clean the last 152 to 254 mm [6 to 10 in] of the exhaust system outlet. Operate the vehicle tor one shift or trip
and inspect the exhaust system outlet for exhaust residue/soot accumulation.
• Inspect the aftertreatment diesel particulate filter.
Refer to Procedure 011-041 in Section 11 .
Snap Acceleration Test
• Monitoring the condition of the exhaust leaving the exhaust system outlet during a Snap Acceleration Test
can reveal the condition of the aftertreatment diesel particulate filter.
• The engine must be at minimum operating temperature or above when completing this test. The vehicle transmission must be in neutral and the vehicle parking brake must be applied.
• Start and idle the engine. Rapidly depress the accelerator pedal from 0 to 100 percent. This can be performed multiple times, if necessary.
• During this test, check for black smoke exiting the exhaust stack, as the engine is accelerated from low
idle to high idle.
NOTE: In some applications, a Snap Acceleration Test may not provide the conditions necessary to reveal a
malfunctioning aftertreatment diesel particulate filter. If there is a heavy buildup of exhaust residue/soot on the
exhaust system outlet and a Snap Acceleration Test does not reveal a condition outlined in the following steps, it
may be necessary to perform:
• A stall test. Refer to Procedure 014-008 in Section 14
• A brief acceleration run under partial to full load.
NOTE: If an opacity meter is used to measure the condition of the exhaust gas leaving the exhaust system
outlet, the engine and aftertreatment must be at operating temperature.
White smoke can indicate condensation in the exhaust and/or some unburned fuel. White smoke is not an
indication of a malfunction of the aftertreatment system.
If excessive white smoke is present, see the Engine Performance Troubleshooting Tree in Section TI.
Visible gray smoke or faint black smoke out of the exhaust system outlet indicates that the aftertreatment diesel
particulate filter is damaged. Inspect the aftertreatment diesel particulate filter. Refer to Procedure 011-041 in
Section 11.
Visible black smoke out of the exhaust system outlet indicates a malfunction of the aftertreatment diesel
particulate filter.
NOTE: If the vehicle has experienced the diesel particulate lamp illuminating frequently, high exhaust
temperature lamp (if equipped) illuminating frequently, and/or requires frequent stationary regenerations, see the
appropriate troubleshooting symptom tree.
Refer to Aftertreatment Diesel Oxidation Catalyst and Aftertreatment Diesel Particulate Filter Reuse Guidelines,
Bulletin 4021600, for pass or fail guidelines.
