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 Subaru Forester X LimitedFACTORY OEM SERVICE PROCEDURE
LAN Communication System DTCS
LAN COMMUNICATION SYSTEM DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Refer To |
|---|---|---|
| B1100 | Integ. Unit System Error | < Ref. to DTC B1100 INTEG. UNIT SYSTEM ERROR , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1101 | BATT p/supply malfunction cont. | < Ref. to DTC B1101 BATT P/SUPPLY MALFUNCTION CONT , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1102 | BATT p/supply malfunction backup | < Ref. to DTC B1102 BATT P/SUPPLY MALFUNCTION BACKUP , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1103 | Ignition power failure | < Ref. to DTC B1103 IGNITION POWER FAILURE , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1104 | ACC power failure | < Ref. to DTC B1104 ACC POWER FAILURE , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1105 | Key interlock circuit abnormal | < Ref. to DTC B1105 KEY INTERLOCK CIRCUIT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1106 | shift lock circuit Failure | < Ref. to DTC B1106 SHIFT LOCK CIRCUIT FAILURE , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1201 | CAN-HS counter abnormal | < Ref. to DTC U1201 CAN-HS COUNTER ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1202 | CAN-HS bus off | < Ref. to DTC U1202 CAN-HS BUS OFF , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1211 | CAN-HS ECM data abnormal | < Ref. to DTC U1211 CAN-HS ECM DATA ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1212 | CAN-HS TCM data abnormal | < Ref. to DTC U1212 CAN-HS TCM DATA ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1213 | CAN-HS VDC/ABS data abnormal | < Ref. to DTC U1213 CAN-HS VDC/ABS DATA ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1221 | CAN-HS ECM no-receive data | < Ref. to DTC U1221 CAN-HS ECM NO-RECEIVE DATA , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1222 | CAN-HS TCM no-receive Data | < Ref. to DTC U1222 CAN-HS TCM NO-RECEIVE DATA , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1223 | CAN-HS VDC/ABS no-receive data | < Ref. to DTC U1223 CAN-HS VDC/ABS NO-RECEIVE DATA , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1300 | CAN-LS malfunction | < Ref. to DTC U1300 CAN-LS MALFUNCTION , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1301 | CAN-LS counter abnormal | < Ref. to DTC U1301 CAN-LS COUNTER ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1302 | CAN-LS bus off | < Ref. to DTC U1302 CAN-LS BUS OFF , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1311 | CAN-LS meter unit data abnormal | < Ref. to DTC U1311 CAN-LS METER UNIT DATA ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| U1321 | CAN-LS meter no-receive data | < Ref. to DTC U1321 CAN-LS METER NO-RECEIVE DATA , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1401 | M Collation NG | < Ref. to DTC B1401 M COLLATION NG , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1402 | Immobilizer Key Collation NG | < Ref. to DTC B1402 IMMOBILIZER KEY COLLATION NG , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1403 | E/G request NG | < Ref. to DTC B1403 E/G REQUEST NG , Diagnostic Procedure with Diagnostic Trouble Code (DTC). > |
| B1500 | Keyless UART com. Malfunction | < Ref. to DTC B1500 KEYLESS UART COM. MALFUNCTION , 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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