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.
2012 Lexus IS 350 Base, AWDFACTORY OEM SERVICE PROCEDURE
NAVIGATION SYSTEM (for HDD)
NAVIGATION SYSTEM (FOR HDD) DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION
| DTC Code | Description |
|---|---|
| B156A | Gateway ECU Disconnected |
| B156B | Multi-media Interface ECU Disconnected |
| B156E | No Response from Multi-media Interface ECU |
| B1590 | No Response from Gateway ECU |
| B1591 | No Response from Audio HU |
| B1593 | No Response from Stereo Component Amplifier |
| B15A0 | LAN Master Malfunction |
| B15AD | Navigation Processor Malfunction |
| B15B0 | Display Screen Malfunction |
| B15B8 | Harddisk Malfunction |
| B15C0 | Short in GPS Antenna |
| B15C1 | Open in GPS Antenna |
| B15C2 | Speed Signal Malfunction |
| B15D0 | MOST Communication Malfunction |
| B15D1 | Audio HU Disconnected |
| B15D3 | Stereo Component Amplifier Disconnected |
| B15E7 | Harddisk Reading/Writing Malfunction(Low Temperature) |
| B15E8 | Harddisk Reading/Writing Malfunction(High Temperature) |
| U0073 | Control Module Communication Bus Off |
| U1110 | Lost Communication with Clearance Warning ECU |
Factory Service Tools
Use the Manual With the Right Hardware
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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.
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