Diagnostic & Repair Guides

RX 450h Cold-Start Misfire: L-SB-0045-12 Decision Path

A non-substitutive summary of the OEM decision path; technicians must use the current bulletin and applicable model-year repair manual.

Overview

This guide is a navigation summary of Lexus L-SB-0045-12 Rev1, not a replacement for the copyrighted bulletin or the model-year repair manual. It applies only to the stated US-market 2010–2017 RX 450h condition: initial cold-soak rough running and/or one of P0300 through P0306.

Confirm the condition and codes, perform the complete applicable misfire diagnosis, and stop using this bulletin path if a concern is found in the mechanical engine, engine control, ignition or fuel-supply system. If those checks reveal no concern, inspect injector tips for debris using authorized procedures. Replace all six injectors only for a positive debris finding, then clear DTCs, start the engine and confirm the repair. A negative finding exits to normal diagnosis.

Guide overview

Guide Type Name
Diagnostic Workflow / OEM Bulletin Navigation
Difficulty
Advanced
Estimated Time
Use Current Model-year Labor And Service Information; The Source Lists Warranty Labor By Model Year But This Summary Does Not Reproduce It.
Applicable Vehicles
2010–2017 Lexus RX 450h 2GR-FXE (US Bulletin Scope)

Preparation and safety

Required Tools
Compatible Techstream platform
source specifies software 12.20.024 or later at its revision date
model-year service information
Required Parts Or Consumables
No parts are authorized by this summary. The bulletin lists model-year-specific injector and gasket parts for the positive-debris branch; verify current supersessions.
Prerequisites
Qualified technician; exact vehicle and market match; cold-soak symptom and/or listed DTC; current L-SB-0045-12 revision and model-year repair manual.
Safety Warnings
Do not attempt fuel-system or hybrid-vehicle work without the training, isolation procedures, fire controls, PPE and service information required for the exact vehicle.

Procedure and verification

Diagnostic Or Repair Steps

1. Confirm bulletin applicability and initial cold-soak roughness and/or P0300–P0306.
2. Perform the applicable repair-manual misfire diagnosis.
3. If no listed system concern is found, inspect removed injector tips for debris.
4. If debris is absent, leave this bulletin path and continue normal diagnosis.
5. If debris is present, follow the official model-year procedure and bulletin parts path.
6. Clear DTCs, start the engine and verify the result.

Measurements And Limits
No universal substitute limits are supplied here. Use the exact model-year repair manual and Techstream data definitions.
Decision Points
Entry condition present?
Any concern in normal misfire diagnosis?
Debris visible on injector tips?
Repair verification successful?
Verification Steps
After the authorized repair, clear stored DTCs, start the engine, confirm the repair, and document the operating condition and scan result.

Technical review & evidence

Technically reviewed

Reviewer: Autool

Reviewed: 2026-08-24 13:39:42 UTC

Source updated: 20171213

References

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