Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSLEXUS2010RX 450H 3.5 BREPAIR AND DIAGNOSISACCESSORIES & EQUIPMENTCOMMUNICATION DEVICESLIN COMMUNICATION SYSTEM (DIAGNOSTICS - INTRODUCTION)LIN COMMUNICATION SYSTEMDIAGNOSTIC TROUBLE CODE CHART (FROM 8/2009)DIAGNOSTIC TROUBLE CODE CHART
2010 Lexus RX 450h 3.5 B
Diagnostic Trouble Code Chart
2010 Lexus RX 450h 3.5 BSECTION Diagnostic Trouble Code Chart
MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
| DTC Code | Detection Item | Trouble Area | See |
|---|---|---|---|
| B1206 | P/W Master Switch Communication Stop | 1. Multiplex network master switch assembly 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Wire harness or connector 5. ECU-B NO. 2 fuse |
Refer to DTC B1206: P/W Master Switch Communication Stop |
| B1273 | Sliding Roof ECU Communication Stop | 1. Sliding roof ECU (sliding roof drive gear assembly) 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Wire harness or connector 5. S/ROOF fuse 6. ECU-B NO. 3 fuse |
Refer to DTC B1273: Sliding Roof ECU Communication Stop |
| B2287 | LIN Communication Master Malfunction | 1. Power management control ECU 2. Certification ECU (smart key ECU assembly) 3. Wire harness or connector |
Refer to DTC B2287: LIN Communication Master Malfunction |
| B2321 | Driver Side Door ECU Communication Stop | 1. Front power window regulator motor assembly LH 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Multiplex network master switch assembly 5. Wire harness or connector 6. FL DOOR fuse |
Refer to DTC B2321: Driver Side Door ECU Communication Stop |
| B2322 | Front Passenger Side Door ECU Communication Stop | 1. Front power window regulator motor assembly RH 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Wire harness or connector 5. FR DOOR fuse |
Refer to DTC B2322: Front Passenger Side Door ECU Communication Stop |
| B2323 | Rear Door RH ECU Communication Stop | 1. Rear power window regulator motor assembly RH 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Wire harness or connector 5. RR DOOR fuse |
Refer to DTC B2323: Rear Door RH ECU Communication Stop |
| B2324 | Rear Door LH ECU Communication Stop | 1. Rear power window regulator motor assembly LH 2. Main body ECU (multiplex network body ECU) 3. Instrument panel junction block assembly 4. Wire harness or connector 5. RL DOOR fuse |
Refer to DTC B2324: Rear Door LH ECU Communication Stop |
| B2325 | LIN Communication Bus Malfunction | 1. Front power window regulator motor assembly LH 2. Front power window regulator motor assembly RH 3. Rear power window regulator motor assembly RH 4. Rear power window regulator motor assembly LH 5. Multiplex network master switch assembly 6. Sliding roof ECU (sliding roof drive gear assembly) 7. Main body ECU (multiplex network body ECU) 8. Instrument panel junction block assembly 9. Wire harness or connector |
Refer to DTC B2325: LIN Communication Bus Malfunction |
| B2424 | Headlight Leveling Motor LH Communication Malfunction | 1. Headlight leveling motor LH 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly) |
Refer to DTC B2424: Headlight Leveling Motor LH Communication Malfunction; DTC B2425: Headlight Leveling Motor RH Communication Malfunction |
| B2425 | Headlight Leveling Motor RH Communication Malfunction | 1. Headlight leveling motor RH 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly) |
Refer to DTC B2424: Headlight Leveling Motor LH Communication Malfunction; DTC B2425: Headlight Leveling Motor RH Communication Malfunction |
AFS ECU (HEADLIGHT SWIVEL ECU ASSEMBLY)
| DTC Code | Detection Item | Trouble Area | See |
|---|---|---|---|
| B124D | Lost Communication with AFS LIN | 1. Inner rear view mirror assembly 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly) |
Refer to DTC B124D: Lost Communication with AFS LIN; DTC B2432: Lost Communication with Automatic High Beam Sensor |
| B2410 | Headlight Swivel Motor LH Communication Malfunction | 1. Headlight swivel motor LH 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly) |
Refer to DTC B2410: Headlight Swivel Motor LH Communication Malfunction; DTC B2411: Headlight Swivel Motor RH Communication Malfunction |
| B2411 | Headlight Swivel Motor RH Communication Malfunction | 1. Headlight swivel motor RH 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly |
Refer to DTC B2410: Headlight Swivel Motor LH Communication Malfunction; DTC B2411: Headlight Swivel Motor RH Communication Malfunction |
| B2432 | Lost Communication with Automatic High Beam Sensor | 1. Inner rear view mirror assembly 2. Wire harness or connector 3. AFS ECU (headlight swivel ECU assembly) |
Refer to DTC B124D: Lost Communication with AFS LIN; DTC B2432: Lost Communication with Automatic High Beam Sensor |
CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
| DTC Code | Detection Item | Trouble Area | See |
|---|---|---|---|
| B2785 | Communication Malfunction between ECUs Connected by LIN | 1. Certification ECU (smart key ECU assembly) 2. Power management control ECU 3. Steering lock ECU (steering lock actuator assembly) 4. ID code box (immobiliser code ECU) 5. Wire harness or connector |
Refer to DTC B2785: Communication Malfunction between ECUs Connected by LIN |
| B2786 | No Response from Steering Lock ECU | 1. Steering lock ECU (steering lock actuator assembly) 2. Certification ECU (smart key ECU assembly) 3. Wire harness or connector 4. STR LOCK fuse |
Refer to DTC B2786: No Response from Steering Lock ECU |
| B2789 | No Response from ID BOX | 1. ID code box (immobiliser code ECU) 2. Certification ECU (smart key ECU assembly) 3. Wire harness or connector 4. IMMOBI fuse |
Refer to DTC B2789: No Response from ID BOX |
| B278C | Lost Communication with Power Source Control | 1. Power management control ECU 2. Certification ECU (smart key ECU assembly) 3. Wire harness or connector 4. AM2 fuse |
Refer to DTC B278C: Lost Communication with Power Source Control |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.