HOSE AS 5389144 - 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
Some Tier 4 D8T Track-Type Tractors have been failing high speed regenerations. The machine will attempt a high speed regeneration when the soot loading gets to the appropriate level and the ARD will fail to ignite. After the failure the ECM will log an E1025 : Aftertreatment #1 Failed to Ignite or E1026 : Aftertreatment #1 Loss of Combustion event code with no other associated codes. Technicians have confirmed on multiple machines that the regeneration system is working properly.Note: The machines will continue to complete low speed regenerations successfully.Solution
If a machine will not complete high speed regenerations, and logs an E1025 : Aftertreatment #1 Failed to Ignite or E1026 : Aftertreatment #1 Loss of Combustion event code, the technician needs to follow the troubleshooting procedure to confirm that no other system or hardware failures exist. If all systems are working properly and the machine continues to have a high speed regeneration issue, then replace the ARD combustion air valve. An ARD combustion air valve should only be replaced after all proper troubleshooting for the E1025 : Aftertreatment #1 Failed to Ignite or E1026 : Aftertreatment #1 Loss of Combustion event code has taken place.Note: If a machine fails to do a high speed regeneration and a new valve is not immediately available to install, then the machine operator should be instructed on how to perform a low speed regeneration until the valve is replaced. The operator may need to key cycle the ignition after an E1025 : Aftertreatment #1 Failed to Ignite or E1026 : Aftertreatment #1 Loss of Combustion event occurs. This key cycle must be performed before a low speed regeneration can be completed.