International A26 Derate: Codes and Conditions Before Parts
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Quick answer: Save the complete SPN/FMI, reporting module, active/history status, warning messages and actual restriction, together with engine/VIN and software identity. A derate description is not a component diagnosis. A26 engine-protection reactions and SCR inducement are different diagnostic contexts; an old bulletin's stage example cannot establish today's countdown or repair. [1] [2]
Application: A26 derate-information planning. Warning/protection examples are copyright 2022. The QLS-program example is historical context. The November 2022 cold-weather example has exact chassis, build, engine-year, fan and eligibility limits. Current matched service information controls diagnosis.
What should happen before collecting diagnostic information?
Follow the actual vehicle's warning instructions. Navistar's A26_EWPS_03212022, copyright 2022, says the vehicle should be safely pulled over and parked as soon as possible when the red stop lamp appears. Its engine-protection feature monitors critical engine information, including cooling and lubrication data, with reactions that depend on configuration. [1]
Once safely parked, preserve the exact message and lamp combination. Describe whether the truck lost pulling power, was held at idle, showed a road-speed restriction, stopped, or simply felt weak without an identified restriction. Do not conduct another road trial to find a countdown.
Which code details make an A26 report useful?
Send the complete scan report rather than a cropped picture of one number. Keep each SPN and FMI together, its reporting controller, exact diagnostic-tool description, active or historical status, available event data and the time the complaint occurred. Ask the provider to mark which information was present before repair and which appeared during testing.
| Keep | Record precisely | Question for the provider |
|---|---|---|
| Fault identity | Full SPN/FMI, module and description. | Which matched diagnostic path applies? |
| Event status | Active/history, times and available snapshot. | Which finding explains this event? |
| Restriction | Actual message, power/speed/idle behavior. | What limitation is confirmed? |
| Application | Engine serial/year, VIN, chassis and software. | Which current instructions were selected? |
Retain the original report before any service action changes it. If only a dashboard message is available, state that limitation. An unrecorded code should remain unknown rather than being reconstructed from an internet list.
What does the dated SPN 5246 example actually show?
Figure 2 of IK0700115 revision 18, January 10, 2023, distinguishes SPN 5246 FMI 15, FMI 16 and FMI 0 as different SCR-inducement stages. Keep the FMI; the SPN alone does not identify the stage or initiating defect. The bulletin's January update states the A26 QLS emergency calibration was no longer available after December 31, 2022. [2]
This is historical coding context, not a current programming recommendation. Ask the service provider to identify the installed software, initiating fault and approved repair/recovery instructions. This guide gives no universal timing ladder, percentage reduction or reset command.
Why keep weather, chassis and equipment details?
Service Procedure 22515, November 2022, describes extreme-cold intake-manifold-pressure sensor icing as a derate example. Its stated population is certain HV, HX, LT and RH trucks built September 21, 2021 through July 8, 2022, with MY2022 A26 engines and two-speed fan drive; eligibility also requires the vehicle to be marked in the service portal. [3]
Keep the actual weather, load, speed/idle condition and vehicle identity with the event report. A similar symptom does not establish that campaign's applicability or a failed sensor. Have a dealer check current vehicle-specific campaign status separately.
What should the work order establish before replacement?
Ask for the selected procedure, completed tests, measured results with conditions, established defect and proposed repair. Keep the reason for a restriction separate from the part named on a quote. If the provider could not complete a test, retain what prevented it and the next required finding.
After repair, request the fault-status report and the specified confirmation that the original complaint and operating restriction have been addressed. Do not substitute a cleared display for that record. When the report concerns cooling loss or temperature, the A26 cooling-evidence guide helps organize that separate complaint.
What belongs with an A26 parts inquiry?
Provide the confirmed component finding, installed engine serial/emissions record, VIN/chassis, software history where relevant and actual component markings. International's Service Information overview describes VIN-based service/parts information filtered by engine and vehicle features. [4] Use the A26 identification guide for the application record.
Send the diagnosed application for confirmation
Use ATP's part-fitment request. Ask the quote to confirm the application, supplied item and included installation parts; availability requires confirmation.
Common A26 derate questions
Does SPN 5246 identify one failed DEF part?
The cited historical example describes inducement stages. Obtain the initiating-fault diagnosis before ordering a component.
Should the FMI be included with the SPN?
Yes. Send the full code and original controller description with the complete report.
Is the old QLS emergency calibration a current repair option?
The cited bulletin records its end. Obtain current vehicle-specific software and repair instructions.
Does cold-weather derate establish recall 22515 eligibility?
No. Its stated population and portal eligibility must be checked for the exact vehicle.
Will every A26 derate follow one countdown?
Use the actual message, configuration and current matched instructions. This overview supplies no universal countdown.
Technical sources and application notes
These primary manufacturer documents support the stated examples. Dated bulletins explain diagnostic distinctions; the current service information for your engine controls the repair. ATP prepared this editorial guide; no independent technician review is claimed.
- Navistar, International A26 (2022), Engine Warning and Protection System A26_EWPS_03212022, copyright 2022, printed pages 1-2. Red-stop response and selectable warning/protection behavior. Official International PDF; no universal countdown or threshold asserted.
- Navistar, IK0700115, QLS Emergency Calibration, revision 18, January 10, 2023. Manufacturer bulletin reproduced in readable public form by OEMDTC; Figure 2 distinguishes SPN 5246 FMI 15, 16 and 0. January update says A26 emergency calibration was no longer available after December 31, 2022. Historical context only.
- Navistar, Service Procedure 22515, November 2022. Certain HV, HX, LT and RH trucks built September 21, 2021 through July 8, 2022, with MY2022 A26 and two-speed fan drive; portal-marked eligibility. Extreme-cold IMP-sensor icing example. Manufacturer PDF hosted by NHTSA.
- International, Service Information, manufacturer overview checked November 2, 2026. VIN-based parts/service lookup with engine, model, vendor and feature filters.
