PLATE 3566654 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Engine may run at an elevated low idle speed on the machines listed above. Certain F2 Backhoe Loaders, equipped with Tier 4 engines may automatically increase the low idle speed to 1200 rpm when the parking brake is applied. The SCR aftertreatment system will also log error codes 5246-15 and 1235-9 (Aftertreatment SCR Operator Inducement Severity: High - Least Severe) and bringing on the warning lamp. This happens when the machine is being operated at low engine speeds (1200rpm) and low hydraulic load.Solution
Apply parking brake when operating the hoe. Especially when the engine speed is below 1500rpm or when the machine is working under low hydraulic load.If the engine speed increases to 1200rpm with the parking brake engaged, then the engine is performing an SCR cleaning process which is normal. For information regarding the SCR refer to Operation Maintenance Manual, SEBU9215, "Selective Catalytic Reduction Warning System".Note: There is no fault with the machine and the machine will continue to work as designed. Increasing the engine speed and/or placing more load on the engine will create enough exhaust temperature to perform the required function without increasing the engine RPM at idle.Note: If the operator uses the parking brake, the error codes or warning lamp should not appear.