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.
2015 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE
Keyless Access System
KEYLESS ACCESS SYSTEM DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Item | Description |
|---|---|---|
| U0073 | Control Module Communication Bus Off | <Ref. to DTC U0073 CONTROL MODULE COMMUNICATION BUS OFF , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0100 | Lost Communication With ECM/PCM "A" | <Ref. to DTC U0100 LOST COMMUNICATION WITH ECM/PCM "A" , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0101 | Lost Communication With TCM | <Ref. to DTC U0101 LOST COMMUNICATION WITH TCM , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0122 | Lost Communication With Vehicle Dynamics Control Module | <Ref. to DTC U0122 LOST COMMUNICATION WITH VEHICLE DYNAMICS CONTROL MODULE , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0140 | Lost Communication With Body Control Module | <Ref. to DTC U0140 LOST COMMUNICATION WITH BODY CONTROL MODULE , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0155 | Lost Communication With Instrument Panel Cluster (IPC) Control Module | <Ref. to DTC U0155 LOST COMMUNICATION WITH INSTRUMENT PANEL CLUSTER (IPC) CONTROL MODULE , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0401 | Invalid Data Received From ECM/PCM "A" | <Ref. to DTC U0401 INVALID DATA RECEIVED FROM ECM/PCM "A" , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| U0422 | Invalid Data Received From Body Control Module | <Ref. to DTC U0422 INVALID DATA RECEIVED FROM BODY CONTROL MODULE , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B1242 | Wireless Tuner Abnormal | <Ref. to DTC B1242 WIRELESS TUNER ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2271 | IGN Fuse Blown or IGN Circuit Abnormal | <Ref. to DTC B2271 IGN FUSE BLOWN OR IGN CIRCUIT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2274 | ACC Monitor | <Ref. to DTC B2274 ACC MONITOR , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2275 | STSW Circuit Abnormal | <Ref. to DTC B2275 STSW CIRCUIT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2276 | ACCR Signal Abnormal | <Ref. to DTC B2276 ACCR SIGNAL ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2277 | Submerging Circuit Abnormal | <Ref. to DTC B2277 SUBMERGING CIRCUIT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2282 | Vehicle Speed Signal Abnormal | <Ref. to DTC B2282 VEHICLE SPEED SIGNAL ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2283 | Vehicle Speed Sensor Fault Detection | <Ref. to DTC B2283 VEHICLE SPEED SENSOR FAULT DETECTION , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2284 | Brake Signal (Cable-Information Does Not Match to Bean-Information) | <Ref. to DTC B2284 BRAKE SIGNAL (CABLE-INFORMATION DOES NOT MATCH TO BEAN-INFORMATION) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2285 | Steering Lock Position Signal Abnormal | <Ref. to DTC B2285 STEERING LOCK POSITION SIGNAL ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2286 | Driving Possible Signal Abnormal | <Ref. to DTC B2286 DRIVING POSSIBLE SIGNAL ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2779 | Remote Control Engine Starter Communication Collation NG | <Ref. to DTC B2779 REMOTE CONTROL ENGINE STARTER COMMUNICATION COLLATION NG , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2781 | Steering Lock ECU Open/Short | <Ref. to DTC B2781 STEERING LOCK ECU OPEN/SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2782 | Steering Lock Power Supply Circuit Abnormal (Smart ECU-Side Abnormal) | <Ref. to DTC B2782 STEERING LOCK POWER SUPPLY CIRCUIT ABNORMAL (SMART ECU-SIDE ABNORMAL) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2784 | Antenna Coil Fault | <Ref. to DTC B2784 ANTENNA COIL FAULT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2785 | LIN Communication Error | <Ref. to DTC B2785 LIN COMMUNICATION ERROR , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2786 | No Response From Steering Lock ECU | <Ref. to DTC B2786 NO RESPONSE FROM STEERING LOCK ECU , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2788 | IGN1 Input Abnormal | <Ref. to DTC B2788 IGN1 INPUT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2789 | ID Code Box No Response | <Ref. to DTC B2789 ID CODE BOX NO RESPONSE , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B278A | Abnormal Immobilizer Power Supply | <Ref. to DTC B278A ABNORMAL IMMOBILIZER POWER SUPPLY , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B278D | ID Code Box Recognition Judgment Abnormal | <Ref. to DTC B278D ID CODE BOX RECOGNITION JUDGMENT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B2790 | ID Code Box Abnormal (EEPROM Abnormal) | <Ref. to DTC B2790 ID CODE BOX ABNORMAL (EEPROM ABNORMAL) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A1 | Driver Side External Antenna Output Stage Open | <Ref. to DTC B27A1 DRIVER SIDE EXTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A2 | Passenger Side External Antenna Output Stage Open | <Ref. to DTC B27A2 PASSENGER SIDE EXTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A5 | Front Internal Antenna Output Stage Open | <Ref. to DTC B27A5 FRONT INTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A6 | Rear Internal Antenna Output Stage Open | <Ref. to DTC B27A6 REAR INTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A7 | Trunk/Rear Gate Internal Antenna Output Stage Open | <Ref. to DTC B27A7 TRUNK/REAR GATE INTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
| B27A8 | Trunk/Rear Gate External Antenna Output Stage Open | <Ref. to DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OUTPUT STAGE OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).> |
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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