Home18-052-26 · JEEP
JEEP

18-052-26

Manufacturer communications

Publication date
2026-05-12
Received by NHTSA
2026-05-20
NHTSA record numbers
11032840

Manufacturer summary

Original wording in English

Flash: Powertrain Control Module (PCM) Updates - PCR8A3 Technicians may find the following Diagnostic Trouble Code (DTC):
• P04B6-00 - Fuel Fill Door Stuck Closed (Stored Status). NOTE: There will be no Malfunction Indicator Lamp (MIL) for this DTC. Customers may also experience one or more of the following:
• The vehicle will not start and cannot be keyed off. NOTE: The vehicles 12V system remains powered up.
• Poor combustion stability or "wavy" engine RPM oscillations during engine warm-ups.
• Engine Stop/Start (ESS) bumps or lack of refinement.
• Noisy/poor starts in extreme cold temperatures.
• Perceived after-run pump noise after vehicle is turned off. The following software enhancements are also available:
• Diagnostic improvements for DTCs, P013A-00, P013B-00, P013E-00 and P013F-00.
• Improved transitions between engine operating modes for emissions robustness.
• Scan tool improvement to show accurate state of after-run pump.
• Scan tool improvements for EVAP system data.
• Improved combustion stability during warm-up and catalyst-reheating mode.
• Improved ESS refinements.
• Optimization of after-run pump usage for lower 12V usage and perceived customer noise.
• Disablement of DTC P04B6-00 for falsely setting.
• Calibration update for EVAP system Service Leak Test.
• Improved engine starts at extreme low temperatures. This bulletin involves inspecting and possibly reprogramming the Battery Pack Control Module (BPCM), Drive Motor Power Inverter (DMPI), Electric Vehicle Control Unit (EVCU) and PCM with the latest available software.

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MakeModelModel year
JeepCHEROKEE2026

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