- Turn ignition off. Connect scan tool. Start engine. Observe display for mass airflow and voltage signal values from MAF sensor. If values are between 1.3 g/sec and 250 g/sec or .3-5.0 volts, system is normal. Check for poor connections or intermittent open circuits. If values are not within specifications, go to next step.
- Turn ignition and scan tool off. Disconnect MAF sensor. Turn ignition and scan tool on. Observe display for mass airflow and voltage signal from MAF sensor. If values are less than 250 g/sec or 5.0 volts, replace MAF sensor. If values are greater than 250 g/sec or 5.0 volts, check for short to power in harness between MAF sensor and PCM. After repairing short, check PCM operation and replace if necessary. Retest system.
Home/Subaru/Forester/Subaru Forester SF (1997-2000)/Repair manual/Testing & Diagnostics/DTC P0103 (QA_HI): MASS AIRFLOW (MAF) SENSOR CIRCUIT HIGH I…
Contents
Wiring diagrams Section: Testing & Diagnostics- Engine Controls - Tests W/codes: Diagnosis
- Engine Controls - Tests W/codes: Component Locations
- Engine Controls - Tests W/codes: Other
- DTC P0101 (QA_R): MASS AIRFLOW (MAF) SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM
- DTC P0102 (QA_LOW): MASS AIRFLOW (MAF) SENSOR CIRCUIT LOW INPUT
- DTC P0103 (QA_HI): MASS AIRFLOW (MAF) SENSOR CIRCUIT HIGH INPUT
- DTC P0106 (P_R): PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM
- DTC P0107 (P_SLOW): PRESSURE SENSOR CIRCUIT LOW INPUT
- DTC P0108 (P_SHI): PRESSURE SENSOR CIRCUIT HIGH INPUT
- DTC P0116 (TW_LOW): ECT SENSOR CIRCUIT LOW INPUT (LEGACY)
- DTC P0117 (TW_LOW): ECT SENSOR CIRCUIT LOW INPUT (FORESTER & IMPREZA)
- DTC P0117 (TW_HI): ECT SENSOR CIRCUIT HIGH INPUT (LEGACY)
- DTC P0118 (TW_HI): ECT SENSOR CIRCUIT HIGH INPUT (FORESTER & IMPREZA)
- DTC P0121 (TH_R): THROTTLE POSITION (TP) SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM
- DTC P0122 (THV_LOW): TP SENSOR CIRCUIT LOW INPUT
- DTC P0123 (THV_HI): TP SENSOR CIRCUIT LOW INPUT
- DTC P0125 (TW_CL): INSUFFICIENT ENGINE COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL
- DTC P0130 (FO2_V): FRONT O2S CIRCUIT MALFUNCTION
- DTC P0133 (FO2_R): FRONT O2S CIRCUIT SLOW RESPONSE
- DTC P0135 (FO2H): FRONT O2S HEATER CIRCUIT MALFUNCTION
- DTC P0136 (RO2_V): REAR O2S CIRCUIT MALFUNCTION
- DTC P0139 (RO2_R): REAR O2S CIRCUIT SLOW RESPONSE
- DTC P0141 (RO2_H): REAR O2S HEATER CIRCUIT MALFUNCTION
- DTC P0170 (FUEL): FUEL TRIM MALFUNCTION
- DTC P0181 (TNKT-F): FUEL TEMPERATURE SENSOR A CIRCUIT RANGE/PERFORMANCE
- DTC P0182 (TNKT_LOW): FUEL TEMPERATURE SENSOR A CIRCUIT LOW INPUT
- DTC P0183 (TNKT_HI): FUEL TEMPERATURE SENSOR "A" CIRCUIT HIGH INPUT
- DTC P0261, DTC P0264, DTC P0267 & DTC P0270: FUEL INJECTOR CIRCUIT LOW INPUT
- DTC P0262, P0265, P0268 OR P0271: FUEL INJECTOR CIRCUIT HIGH INPUT
- DTC P0301-DTC P0304: CYLINDER MISFIRE DETECTED
- DTC P0325 (KNOCK): KNOCK SENSOR 1 (KS) CIRCUIT MALFUNCTION
- DTC P0335 (CRANK): CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT MALFUNCTION
- DTC P0336 (CRANK_R): CRANKSHAFT POSITION (CKP) SENSOR RANGE/PERFORMANCE PROBLEM
- DTC P0340 (CAM): CAMSHAFT POSITION (CMP) SENSOR CIRCUIT MALFUNCTION
- DTC P0341 (CAM_R): CAMSHAFT POSITION (CMP) SENSOR RANGE/PERFORMANCE PROBLEM
- DTC P0400 (EGR): EGR FLOW MALFUNCTION
- DTC P0403 (ERGSOL): EGR CIRCUIT LOW INPUT
- DTC P0420 (CAT): CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD
- DTC P0440 (EVAP): EVAP EMISSION CONTROL SYSTEM
- DTC P0441 (CPC_F): EVAP EMISSION CONTROL SYSTEM INCORRECT PURGE FLOW
- DTC P0443 (CPC): EVAP EMISSION CONTROL SYSTEM PURGE CONTROL VALVE CIRCUIT LOW INPUT
- DTC P0446 (VCMSOL_LOW): EVAP EMISSION CONTROL SYSTEM VENT CONTROL LOW INPUT
- DTC P0451 (TNKP_F): EVAP EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE
- DTC P0452 (TNKP_LOW): EVAP EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT (FORESTER & 2.5L IMPREZA)
- DTC P0452 (TNKP_LOW): EVAP EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT (LEGACY & 2.2L IMPREZA)
- DTC P0453 (TNKP_HI): EVAP EMISSION CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT (ALL EXCEPT LEGACY)
- DTC P0453 (TNKP_HI): EVAP EMISSION CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT (LEGACY)
- DTC P0461 (FLVL_R): FUEL LEVEL SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM
- DTC P0463 (FLVL_HI): FUEL LEVEL SENSOR CIRCUIT HIGH INPUT
- DTC P0480 COOLING FAN RELAY NO. 1 LOW INPUT
- DTC P0483 COOLING FAN FUNCTION PROBLEM
- DTC P0500 (VSP): VEHICLE SPEED SENSOR (FORESTER & IMPREZA) (VSS) MALFUNCTION
- DTC P0500 (VSP): VEHICLE SPEED SENSOR (LEGACY) (VSS) MALFUNCTION
- DTC P0505 (ISC): IDLE CONTROL SYSTEM MALFUNCTION
- DTC P0506 (ISC_RLOW): IDLE CONTROL SYSTEM RPM LOWER THAN EXPECTED
- DTC P0507 (ISC_RHI): IDLE CONTROL SYSTEM RPM HIGHER THAN EXPECTED
- DTC P0600: SERIAL COMMUNICATION LINK MALFUNCTION
- DTC P0601 (RAM): INTERNAL CONTROL MODULE MEMORY CHECK SUM ERROR
- DTC P1100 (ST_SWOFF): STARTER SWITCH CIRCUIT LOW INPUT
- DTC P1101 (N_SWOFF): NEUTRAL POSITION SWITCH CIRCUIT MALFUNCTION (A/T)
- DTC P1101 (N_SW): NEUTRAL POSITION SWITCH CIRCUIT MALFUNCTION (M/T)
- DTC P1102 (BR): PRESSURE SOURCES SWITCHING SOLENOID VALVE CIRCUIT LOW INPUT
- DTC P1103 (TRQ): ENGINE TORQUE CONTROL SIGNAL CIRCUIT MALFUNCTION
- DTC P1120 (ST_SWON): STARTER SWITCH CIRCUIT HIGH INPUT
- DTC P1121 (N_SWON): NEUTRAL POSITION SWITCH CIRCUIT LOW INPUT (A/T)
- DTC P1122 (BR_HI): PRESSURE SOURCES SWITCHING SOLENOID VALVE CIRCUIT HIGH INPUT
- DTC P1141 (QA_RHI): MASS AIRFLOW SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM (HIGH INPUT)
- DTC P1142 (TH_RLOW): THROTTLE POSITION SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM (LOW INPUT)
- DTC P1143 (PS_RLOW): PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM (LOW INPUT)
- DTC P1144 (PS_RHI): PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM (HIGH INPUT)
- DTC P1400 (PCVSOL_LO): FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT LOW INPUT
- DTC P1420 (PCVSOL_HI): FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT HIGH INPUT
- DTC P1421 (EGRSOL_HI): EXHAUST GAS RECIRCULATION CIRCUIT HIGH INPUT
- DTC P1422 (CPC_HI): EVAP EMISSION CONTROL VALVE CIRCUIT HIGH INPUT
- DTC P1423 (VCMSOL_HI): EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT HIGH INPUT
- DTC P1440 (PCV_FLOW): FUEL TANK PRESSURE CONTROL SYSTEM FUNCTION PROBLEM LOW INPUT
- DTC P1441 (PCV_FHI): FUEL TANK PRESSURE CONTROL SYSTEM FUNCTION PROBLEM HIGH INPUT
- DTC P1442 (FLVL_R2): FUEL LEVEL SENSOR CIRCUIT RANGE/PERFORMANCE PROBLEM 2
- DTC P1443 EVAP VENT CONTROL FUNCTION PROBLEM (2.2L IMPREZA & ALL LEGACY MODELS)
- DTC P1507 (ISC_SHI): IDLE CONTROL SYSTEM MALFUNCTION (FAIL-SAFE)
- DTC P1520 (FAN_1HI): RADIATOR FAN RELAY 1 CIRCUIT HIGH INPUT
- DTC P1540 (VSP_S): VEHICLE SPEED SENSOR MALFUNCTION 2
- Engine Controls - System/component Tests: Overview
- Engine Controls - System/component Tests: Diagnosis
- Engine Controls - System/component Tests: Other
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