Home/Honda/S2000/Honda S2000 AP1 (1999-2003)/Repair manual/Testing & Diagnostics/DTC P0112: IAT Sensor Circuit Low Voltage

Contents

Wiring diagrams Section: Testing & Diagnostics

Pgm-Fi System: Overview
Pgm-Fi System: Diagnosis
DTC P0107: MAP Sensor Circuit Low Voltage
DTC P0108: MAP Sensor Circuit High Voltage
DTC P0112: IAT Sensor Circuit Low Voltage
DTC P0113: IAT Sensor Circuit High Voltage
DTC P0116: ECT Sensor Circuit Range/Performance Problem
DTC P0117: ECT Sensor Circuit Low Voltage
DTC P0118: ECT Sensor Circuit High Voltage
DTC P0122: TP Sensor Circuit Low Voltage
DTC P0123: TP Sensor Circuit High Voltage
DTC P0125: ECT Sensor Malfunction/Slow Response (2004-2005 models)
DTC P0128: Cooling System Malfunction (2002-2005 models)
DTC P0131: Primary HO2S (Sensor 1) Circuit Low Voltage (2000-2003 models)
DTC P0131: Primary HO2S (Sensor 1) Circuit Low Voltage (2004-2005 models)
DTC P0132: Primary HO2S (Sensor 1) Circuit High Voltage (2000-2003 models)
DTC P0132: Primary HO2S (Sensor 1) Circuit High Voltage (2004-2005 models)
DTC P0133: Primary HO2S (Sensor 1) Circuit Slow Response
DTC P0134: Primary HO2S (Sensor 1) Heater System Malfunction (2004 model)
DTC P0134: Primary HO2S (Sensor 1) Heater System Malfunction (2005 model)
DTC P0135: Primary HO2S (Sensor 1) Heater Circuit Malfunction; DTC P0141: Secondary HO2S (Sensor 2) Heater Circuit Malfunction
DTC P0137: Secondary HO2S (Sensor 2) Circuit Low Voltage
DTC P0138: Secondary HO2S (Sensor 2) Circuit High Voltage (2000-2004 models)
DTC P0138: Secondary HO2S (Sensor 2) Circuit High Voltage (2005 model)
DTC P0139: Secondary HO2S (Sensor 2) Circuit Slow Response (2000-2004 models)
DTC P0171: Fuel System Too Lean; DTC P0172: Fuel System Too Rich
DTC P0300: Random Misfire and Any Combination of the Following:; DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected
DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected
DTC P0325: Knock Sensor Circuit Malfunction
DTC P0335: CKP Sensor No Signal; DTC P0336: CKP Sensor Circuit Intermittent Interruption (2000-2003 models); DTC P0339: CKP Sensor Circuit Intermittent Interruption (2004-2005 models)
DTC P0340: CMP Sensor A No Signal (2004-2005 models); DTC P0344: CMP Sensor A Circuit Intermittent Interruption (2004-2005 models); DTC P1361: CMP (TDC) Sensor A Circuit Intermittent Interruption (2000-2003 models); DTC P1362: CMP (TDC) Sensor A No Signal (2000-2003 models)
DTC P0365: CMP Sensor B No Signal (2004-2005 models); DTC P0369: CMP Sensor B Circuit Intermittent Interruption (2004-2005 models); DTC P1366: CMP (TDC) Sensor B Circuit Intermittent Interruption (2000-2003 models); DTC P1367: CMP (TDC) Sensor B No Signal (2000-2003 models)
DTC P0500: VSS Circuit Malfunction
DTC P0607: ECM Internal Circuit Malfunction (2004-2005 models); DTC P1607: ECM Internal Circuit Malfunction (2000-2003 models)
DTC P0630: VIN Not Programmed or Mismatch (2004-2005 models)
DTC P1106: BARO Sensor Range/Performance Problem (2000-2003 models); DTC P2227: BARO Sensor Range/Performance Problem (2004-2005 models)
DTC P1107: BARO Sensor Circuit Low Voltage (2000-2003 models); DTC P1108: BARO Sensor Circuit High Voltage (2000-2003 models); DTC P2228: BARO Sensor Circuit Low Voltage (2004-2005 models); DTC P2229: BARO Sensor Circuit High Voltage (2004-2005 models)
DTC P1109: BARO Sensor Circuit Out of Range High (2004-2005 models)
DTC P1121: TP Sensor Signal Lower Than Expected
DTC P1122: TP Sensor Signal Higher Than Expected
DTC P1128: MAP Sensor Signal Lower Than Expected
DTC P1129: MAP Sensor Signal Higher Than Expected
DTC P1297: ELD Circuit Low Voltage
DTC P1298: ELD Circuit High Voltage
DTC P2195: Primary HO2S (Sensor 1) Circuit Low Voltage (2004 model)
DTC P2195: Primary HO2S (Sensor 1) Circuit Low Voltage (2005 model)
DTC P2270: Secondary HO2S (Sensor 2) Circuit Signal Stuck Lean (2004-2005 models)
DTC P2271: Secondary HO2S (Sensor 2) Circuit Signal Stuck Rich (2004-2005 models)
DTC P2297: Primary HO2S (Sensor 1) Circuit High Voltage (2004-2005 models)

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DTC P0112: IAT Sensor Circuit Low Voltage Honda S2000 AP1

Testing & Diagnostics 1 illustration ~268 words

Note. Before you troubleshoot, record all freeze data and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 27

Scheme 27: DTC P0112: IAT Sensor Circuit Low Voltage

Scheme 27: DTC P0112: IAT Sensor Circuit Low Voltage

Turn the ignition switch ON (II).
Check the IAT with a scan tool or the HDS. Is about 302 °F (150 °C) or more, or 0 V indicated? YES - Go to step 3. NO - Go to step 8 .
Disconnect the IAT sensor 2P connector.
Check the IAT with a scan tool or the HDS. Is about 302 °F (150 °C) or more, or 0 V indicated? YES - Go to step 5. NO - Replace the IAT sensor (see «SPECIAL TOOLS»(ref-221324-S23506078702006022400000) ).
Turn the ignition switch OFF.
Disconnect ECM connector C (31P).
Check the continuity between IAT sensor 2P connector terminal No. 2 and body ground. Is there continuity? YES - Repair short in the wire between the ECM (C25) and the IAT sensor. NO - Substitute a known-good ECM (see «HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES»(ref-221328-S04997151962006022400000) ) and recheck. If normal IAT is indicated, replace the original ECM (see «ECM REPLACEMENT»(ref-221329-S30667517252006022400000) ).
Check the temperature reading on the scan tool or the HDS. Be aware that if the engine is warm, the reading will be higher than ambient temperature. If the engine is cold, the IAT and ECT will have the same value. Is the correct ambient temperature indicated? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IAT sensor and at the ECM. NO - Replace the IAT sensor (see «SPECIAL TOOLS»(ref-221324-S23506078702006022400000) ).