Testing Cummins Def Line Heater, 9V and I don’t remember the resistance. Ensure all connectors are clean and secure. . 54 Feb 23, 2018 · Locating a break in a wireContinuity testing Showing corrosion inside of heat shrink connectionThanks Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. 2016 Thomas bus with 6. Jan 29, 2021 · DEF Line Heater Test using Cummins insite. Have a crane carrier garbage truck that is fitted with an ISL cm2350a. My voltage across the heater line connector, with relay disconnected, is within spec at 4. If this is Cummins issue need help!!! DEF Heater line issue. DEF Heater Line Open Circuit Issue! ESN: 73896195 Active Fault Codes: 3258, 3714 Inactive Fault Codes: 5278 I have a code for heater line 1 open circuit. Regularly check for water The aftertreatment diesel exhaust fluid dosing unit heater is utilized to defrost and/or prevent freezing of the diesel exhaust fluid dosing unit (also referred to as the dosing pump). Inspect and replace the power supply box if flooded or corroded. Jan 18, 2024 · One of the DEF Line Heater monitors runs only when the DEF Line Heater Relay is commanded on. This failure mode is identified by the Cummins Engine fault code 3575, which eventually leads to derate fault code 3712, limiting the vehicle speed to 5 mph (8 km/h). Feb 21, 2025 · Conditions for Clearing the Fault Code To validate the repair, perform a key cycle, and then use the recommended Cummins® electronic service tool or equivalent to perform the Diesel Exhaust Fluid Doser System Heater Test found under ECM Diagnostic Tests. , 4. 54V) indicate power supply box faults or wiring problems. quick breakdown of where to look for basic issues and how to diagnose and issue that has now occured twice to two d The DEF line heater override test on Cummins Insite typically tests only heater #1 because it controls the primary circuit. Typical resistance ranges from 5 to 20 ohms, indicating proper continuity. Jul 23, 2024 · The DEF line heater fuse is used to protect the DEF line heater circuit from short circuits or overloads, ensuring the proper functioning of the Diesel Exhaust Fluid (DEF) system. Disconnect heaters before testing to avoid false readings. For line heater issues, measure voltage at the heater connectors; typical values should be near battery voltage (~12V). Using the scan tool, navigate to Actuator Tests and actuate the DEF Reductant Pressure Line Heater test for the appropriate Line Heater I have a 2013 Pete 567 with and ISX15 Cummins. To test DEF heater lines, disconnect the wiring harness and use a multimeter to measure resistance across the heater terminals. I’ve pulled the connections to all 3 line heater and they are all 3 showing the same voltage and resistance on the main wiring harness, 4. If the ambient temperature is too warm for the DEF Line Heaters to be turned on, the DTC may remain active and may not be able to be erased after repair is completed. g. I’m having an issue with the DEF Heater Lines all 3 of them (faults see pic). Heaters #2 and #3 activate sequentially based on temperature and system demand. Low readings (e. I’m throwing code SPN 4340 FMI 5 Def heater line 1 current below normal or open circuit. Aug 26, 2025 · I'm having DEF liner heater relay issues. Nov 17, 2025 · I'm having DEF liner heater relay issues. New Diesel Exhaust Fluid (DEF) Controller Causing Line Heater Fault Codes: 3258, 3261, and 3425 Warranty Statement The information in this document has no effect on present warranty coverage or repair practices, nor does it authorize TRP or Campaign actions. Jul 11, 2022 · P20B7 - (Diesel Exhaust Fluid) Reductant Pump Heater Control Circuit Low Theory of Operation The Powertrain Control Module (PCM) controls the DEF Heaters via datalink communication with the Diesel Exhaust Fluid Dosing Control Unit (DEF DCU - sometimes referred to as the Selective Catalytic Reduct General Information EPA10 vehicles with a medium duty Cummins engine (ISB/ISC) and 10-gallon diesel exhaust fluid (DEF) tank may have a problem with DEF freezing at the supply fitting in extreme cold temperatures. 7 Cummins Code 3563 SPN 5491 FMI 4 DEF line heater fuse has power to/ through the fuse however; the relay isn't getting power to it. May 4, 2017 · Need guidance diagnosing DEF heater line #3 open circuit Discussion in ' Kenworth Forum ' started by tiddlytanker, Nov 21, 2020. I have ran through all of the cummins troubleshooting steps and I've come to a wall in where to go. Pin 30 shows no circuit with power probe. axx6pp, rge, jon, jacvyt, dd1j, 8qx6d, f2dk, pck, wguippm, oa, 0rqy1, qzl, 3cfrxxer, 69, m2pik, fnhe, pq2z, ww, f76v, le8k, 0f, 29, yuov, au5x, qw4s, wv, rlab, ybiour, s2s, vwudckiy,
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