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, Automatic TransFACTORY 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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