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.
2011 Lincoln Navigator 4WDFACTORY OEM SERVICE PROCEDURE
Smart Junction Box (SJB)
SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Action |
|---|---|---|
| B106A | TPMS Sensor Pressure Range Bit Incorrect State | Refer to WHEELS & TIRES . |
| B106B | Tire Pressure Sensor Low Battery | Refer to WHEELS & TIRES . |
| B106C | Tire Pressure Monitor System (TPMS) Low Frequency Subsystem Fault | Refer to WHEELS & TIRES . |
| B106D | Tire Pressure Monitor System (TPMS) Initiators Not Configured | Refer to WHEELS & TIRES . |
| B106E | Solid State Driver Disabled Due to Short Circuit | Go to PINPOINT TEST A . |
| B106F | Module Disabled Due to External Fault | Go to PINPOINT TEST A . |
| B1138 | Memory Full | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B1139 | Invalid Transmitter Identification Code | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B1302 | Accessory Delay Relay Coil Circuit Failure | Refer to WINDOWS & GLASS - GLASS, FRAMES & MECHANISMS . |
| B1304 | Accessory Delay Relay Coil Circuit Short To Battery | Refer to WINDOWS & GLASS - GLASS, FRAMES & MECHANISMS . |
| B1317 | Battery Voltage High | Go to PINPOINT TEST B . |
| B1318 | Battery Voltage Low | Go to PINPOINT TEST C . |
| B1320 | Driver Door Ajar Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B1328 | Passenger Door Ajar Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B1336 | Door Ajar RR Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B1342 | ECU Is Faulted | DIAGNOSE all other DTCs first. If no other DTCs are present, INSTALL a new SJB . Refer to SMART JUNCTION BOX (SJB) in this information. TEST the system for normal operation. |
| B1352 | Ignition Key-In Circuit Failure | Refer to INSTRUMENTATION SYSTEM, MESSAGE CENTER & WARNING CHIMES . |
| B1472 | Lamp Headlamp Input Circuit Short To Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1485 | Brake Pedal Input Short to Battery | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1510 | Flash To Pass Switch Circuit Short To Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1520 | Hood Switch Circuit Open | Refer to ANTI-THEFT SYSTEM - ANTI-THEFT PERIMETER . |
| B1572 | Door Ajar LR Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B1578 | Lamp Park Input Circuit Short To Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1624 | Lamp Keypad Output Open Circuit | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B1626 | Lamp Keypad Output Short Circuit To Ground | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B1688 | Lamp Dome Input Circuit Short To Ground | Refer to INTERIOR LIGHTING SYSTEM . |
| B1696 | Autolamp On Circuit Short To Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1791 | Autolamp Sensor Input Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B1793 | Autolamp Sensor Input Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2008 | Wipers On Signal Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2044 | Left Rear Stop Lamp Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2045 | Left Rear Stop Lamp Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2046 | Right Rear Stop Lamp Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2047 | Right Rear Stop Lamp Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2071 | Hazard Switch Signal Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2077 | Liftgate Ajar Sw Circuit Failure | Refer to INTERIOR LIGHTING SYSTEM . |
| B2212 | Panel Dim Switch Out of Range | Refer to INSTRUMENT CLUSTER ILLUMINATION & INSTRUMENT PANEL ILLUMINATION . |
| B2254 | Front Fog Lamp Switch Failure | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2276 | Less Than Two Transmitters Programmed | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2281 | Right Turn Switch Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2282 | Left Turn Switch Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2425 | Remote Keyless Entry Out of Synchronization | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2477 | Module Configuration Failure | Carry out Programmable Module Installation (PMI) on the SJB . Refer to MODULE COMMUNICATIONS NETWORK - MODULE CONFIGURATION . |
| B2479 | Park Brake Switch Circuit Short to Ground | Refer to INSTRUMENTATION SYSTEM, MESSAGE CENTER & WARNING CHIMES . |
| B2498 | Headlamp Switch Multiple Signals Input Active | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2572 | Brake Shift Interlock Output Circuit Failure | Refer to AUTOMATIC TRANSMISSION EXTERNAL CONTROLS . |
| B2666 | Liftgate Release Switch Circuit Failure | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2667 | Liftglass Release Switch Circuit Failure | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B273A | Liftgate Release Output Circuit Shorted to Ground | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B273B | Liftgate Release Output Circuit Open or Shorted to Battery Voltage | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2794 | 3rd Row Power Fold Circuit Failure | Refer to SEAT SYSTEM . |
| B2844 | Ignition Fault | Refer to STEERING COLUMN SWITCHES . |
| B2868 | Left Front Tire Pressure Sensor Fault | Refer to WHEELS & TIRES . |
| B2869 | Right Front Tire Pressure Sensor Fault | Refer to WHEELS & TIRES . |
| B2870 | Right Rear Tire Pressure Sensor Fault | Refer to WHEELS & TIRES . |
| B2871 | Left Rear Tire Pressure Sensor Fault | Refer to WHEELS & TIRES . |
| B2872 | Tire Pressure Sensor Fault | Refer to WHEELS & TIRES . |
| B287A | Tire Pressure System Fault | Refer to WHEELS & TIRES . |
| B287B | Incorrect Tire Pressure Sensor Installed | Refer to WHEELS & TIRES . |
| B29B7 | White Lighting Output Circuit Open | Refer to INSTRUMENT CLUSTER ILLUMINATION & INSTRUMENT PANEL ILLUMINATION . |
| B29B8 | White Lighting Output Circuit Short to Ground | Refer to INSTRUMENT CLUSTER ILLUMINATION & INSTRUMENT PANEL ILLUMINATION . |
| B2A20 | Ignition Stuck in START | Refer to STEERING COLUMN SWITCHES . |
| B2A21 | One or More Configuration Files Missing or Corrupt | Carry ut Programmable Module Installation (PMI) on the SJB . Refer to o MODULE COMMUNICATIONS NETWORK - MODULE CONFIGURATION . CLEAR the DTCs. REPEAT the self-test. If DTC B2A21 is retrieved again, INSTALL a new SJB . Refer to SMART JUNCTION BOX (SJB) in this information. TEST the system for normal operation. |
| B2A22 | Headlamp OFF Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A23 | High Beam Input Circuit Short To Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A24 | Turn Signal Input Circuit Failure | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A25 | Trim Panel Lock Switch Circuit Failure | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2A26 | Keypad Switch Circuit Failure | Refer to HANDLES, LOCKS, LATCHES & KEYLESS ENTRY SYSTEM . |
| B2A27 | Right Front Turn Lamp Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A28 | Right Front Turn Lamp Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A29 | Left Front Turn Lamp Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A2A | Left Front Turn Lamp Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A2D | 3rd Row Power Fold Circuit Short to Ground | Refer to SEAT SYSTEM . |
| B2A2E | Right Front Lamp Low Beam Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A2F | Right Front Lamp Low Beam Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A30 | Left Front Lamp Low Beam Circuit Open | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A31 | Left Front Lamp Low Beam Circuit Short to Ground | Refer to EXTERIOR LIGHTING SYSTEM . |
| B2A32 | LED Backlighting Output Circuit Open | Refer to INSTRUMENT CLUSTER ILLUMINATION & INSTRUMENT PANEL ILLUMINATION . |
| B2A33 | LED Backlighting Output Circuit Short to Ground | Refer to INSTRUMENT CLUSTER ILLUMINATION & INSTRUMENT PANEL ILLUMINATION . |
| B2A35 | Interior Lighting Output Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B2A36 | Interior Lighting Output Circuit Short to Ground | Refer to INTERIOR LIGHTING SYSTEM . |
| B2A39 | Puddle Lamp Output Circuit Open | Refer to INTERIOR LIGHTING SYSTEM . |
| B2A3A | Puddle Lamp Output Circuit Short to Ground | Refer to INTERIOR LIGHTING SYSTEM . |
| C1125 | Brake Fluid Level Sensor Input Circuit Failure | Refer to INSTRUMENTATION SYSTEM, MESSAGE CENTER & WARNING CHIMES . |
| C2780 | EEU in Manufacturer Sub-State | Refer to WHEELS & TIRES . |
| P062F | Internal Control Module EEPROM Error | Carry out Programmable Module Installation (PMI). Refer to MODULE COMMUNICATIONS NETWORK - MODULE CONFIGURATION . CLEAR the DTCs. REPEAT the self-test. If DTC P062F is retrieved again, INSTALL a new SJB . Refer to SMART JUNCTION BOX (SJB) in this information. TEST the system for normal operation. |
| U0155 | Lost Communication With Instrument Panel Cluster (IC) Control Module | Go to PINPOINT TEST D . |
| U2050 | No Application Present | Carry out PMI for the SJB . Refer to MODULE COMMUNICATIONS NETWORK - MODULE CONFIGURATION . CLEAR the DTCs. REPEAT the self-test. If DTC U2050 is retrieved again, INSTALL a new SJB . Refer to SMART JUNCTION BOX (SJB) in this information. TEST the system for normal operation. |
| U2472 | Unexpected Ignition State | Refer to STEERING COLUMN SWITCHES . |
| U2473 | Unexpected Vehicle Speed (VSS) |
NOTE:
Sets during the self-test if vehicle speed exceeds 3 mph (5 kph) or vehicle speed cannot be determined by the SJB
. VERIFY the speedometer operates correctly.If the speedometer does not operate correctly, refer to INSTRUMENTATION SYSTEM, MESSAGE CENTER & WARNING CHIMES
.If the speedometer operates correctly, the self-test is carried out while the vehicle is moving. STOP the vehicle and REPEAT the self-test. |
Factory Service Tools
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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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