Kenworth T680 PACCAR MX-13 Forced Regen Failure - Code P1496 and P1495

Question

My 2018 T680 keeps kicking out of a parked regen after about 10 minutes. The dash displays an SCR System Fault and I am currently in a 5 MPH derate making it impossible to get to my drop. I can hear the 7th injector clicking but the exhaust temperature never gets high enough to finish the burn.

obd2_owl · Accepted Answer

The issue was a failed Aftertreatment Fuel Pressure Sensor and a cracked doser block. I replaced the Hydrocarbons (HC) Doser Injector (Part #2103445PEX) and the fuel line. Once the new doser was installed and the codes were cleared with DAVIE, the truck completed a full 45-minute regen and the derate was lifted. The total for parts was about $650 and it's a common failure on MX-13 engines over 500k miles.

Jordan Lee · Answer

Take a look at the EGR valve. If it's sticking open, you're getting too much recirculated air and it keeps the combustion temps too low for the DOC to light off properly.

Tom Patel · Answer

Check your DOC inlet temperatures using DAVIE software. If the DOC isn't reaching at least 450 degrees Fahrenheit, the 7th injector won't spray enough fuel to cook the soot out of the DPF.

Brian O'Connor · Answer

Inspect the fuel line going to the aftertreatment injector. Those lines are known to crimp or get plugged with debris, causing a low-flow situation that won't throw a specific 'low pressure' code but will definitely fail a regen.

Kenworth T680 PACCAR MX-13 Forced Regen Failure - Code P1496 and P1495

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