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Home >> Suzuki >> 2008 >> Reno Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 259 (Engine Performance - DTC P0401 - P0507) >> DTC P0402: Exhaust Gas Recirculation (EGR) Flow Excessive >> Diagnostic Aids

Diagnostic Aids

WARNING: This page is about a different car, the 2006 Suzuki Reno and 2006 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.

Due to moisture associated with exhaust systems, the EGR valve may freeze and stick in cold weather at times. After the vehicle is brought into a warm shop for repairs, the valve warms and the problem disappears. By watching the Actual EGR and Desired EGR Positions on a cold vehicle with a scan tool, the fault can be easily verified. Check the Freeze Frame data to determine if the DTC set when the vehicle was cold by viewing the Engine Coolant Temperature (ECT).

The EGR Decel Filter value should always be at -3 or lower. If the EGR Decel Filter number becomes more positive (towards 0 or more), then the EGR system is becoming restricted. Look for possible damage to the EGR pipe or for a restriction caused by carbon deposits in the EGR passages or on the EGR valve.