Acura RL. Manual - part 667

DTC P0112: IAT SENSOR CIRCUIT LOW VOLTAGE

1. Turn the ignition switch ON (II).  

2. Check the IAT SENSOR in the DATA LIST with the HDS. 

Is about 356°F (180°C) or higher, or 0.08 V or less indicated?  

YES - Go to step 3. 

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals 
at the IAT sensor and the PCM 

3. Turn the ignition switch OFF.  

4. Disconnect the IAT sensor 2P connector.  

5. Turn the ignition switch ON (II).  

6. Check the IAT SENSOR in the DATA LIST with the HDS. 

Is about 356°F (180°C) or higher, or 0.08 V or less indicated?  

YES - Go to step 7. 

NO - Go to step 11. 

7. Turn the ignition switch OFF.  

8. Jump the SCS line with the HDS.  

9. Disconnect PCM connector A (31P).  

10. Check for continuity between IAT sensor 2P connector terminal No. 1 and body ground. 

Fig. 11: Checking Continuity Between IAT Sensor 2P Connector Terminal No. 1 And Body 
Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Repair short in the wire between the IAT sensor and the PCM (A5), then go to step 13.

NOTE:

Before you troubleshoot, record all freeze data and any on-board snapshot, 
and review the general troubleshooting information (see GENERAL 
TROUBLESHOOTING INFORMATION ).

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

me 

 

Friday, June 05, 2009 2:34:58 PM

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© 2005 Mitchell Repair Information Company, LLC. 

NO - Go to step 18. 

11. Turn the ignition switch OFF.  

12. Replace the IAT sensor (see IAT SENSOR REPLACEMENT ).  

13. Reconnect all connectors.  

14. Turn the ignition switch ON (II).  

15. Reset the PCM with the HDS.  

16. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).  

17. Check for Temporary DTCs or DTCs with the HDS. 

Is DTC P0112 indicated?  

YES - Check for poor connections or loose terminals at the IAT sensor and the PCM, then go to step 
1. 

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the 
indicated DTCs troubleshooting 

18. Update the PCM if it does not have the latest software (see UPDATING THE PCM ), or substitute a 

known-good PCM (see SUBSTITUTING THE PCM ).  

19. Check for Temporary DTCs or DTCs with the HDS. 

Is DTC P0112 indicated?  

YES - Check for poor connections or loose terminals at the IAT sensor and the PCM. If the PCM was 
updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the 
PCM was substituted, go to step 1. 

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the 
original PCM (see PCM REPLACEMENT ). If any other Temporary DTCs or DTCs are indicated, 
go to the indicated DTCs troubleshooting 

DTC P0113: IAT SENSOR CIRCUIT HIGH VOLTAGE 

1. Turn the ignition switch ON (II).  

2. Check the IAT SENSOR in the DATA LIST with the HDS. 

Is about -40°F( -40°C) or less, or 4.90 V or more indicated?  

YES - Go to step 3. 

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals 
at the IAT sensor and the PCM 

NOTE:

Before you troubleshoot, record all freeze data and any on-board snapshot, 
and review the general troubleshooting information (see GENERAL 
TROUBLESHOOTING INFORMATION ).

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

me 

 

Friday, June 05, 2009 2:34:58 PM

Page 11 

© 2005 Mitchell Repair Information Company, LLC. 

3. Turn the ignition switch OFF.  

4. Disconnect the IAT sensor 2P connector.  

5. Connect IAT sensor 2P connector terminals No. 1 and No. 2 with a jumper wire. 

Fig. 12: Connecting IAT Sensor 2P Connector Terminals No. 1 And No. 2 With Jumper Wire 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

6. Turn the ignition switch ON (II).  

7. Check the IAT SENSOR in the DATA LIST with the HDS. 

Is about -40°F (-40°C) or less, or 4.90 V or more indicated?  

YES - Go to step 8. 

NO - Go to step 18. 

8. Turn the ignition switch OFF.  

9. Remove the jumper wire from the IAT sensor 2P connector.  

10. Turn the ignition switch ON (II).  

11. Measure voltage between IAT sensor 2P connector terminal No. 1 and body ground. 

Fig. 13: Measuring Voltage Between IAT Sensor 2P Connector Terminal No. 1 And Body 
Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there about 5V?  

YES - Go to step 12. 

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

me 

 

Friday, June 05, 2009 2:34:58 PM

Page 12 

© 2005 Mitchell Repair Information Company, LLC. 

NO - Go to step 17. 

12. Turn the ignition switch OFF.  

13. Jump the SCS line with the HDS.  

14. Disconnect PCM connector C (22P).  

15. Connect IAT sensor 2P connector terminal No. 2 to body ground with a jumper wire. 

Fig. 14: Connecting IAT Sensor 2P Connector Terminal No. 2 To Body Ground With Jumper 
Wire 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

16. Check for continuity between PCM connector terminal C12 and body ground. 

Fig. 15: Checking Continuity Between PCM Connector Terminal C12 And Body Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Go to step 25. 

NO - Repair open in the wire between the PCM (C12) and the IAT sensor, then go to step 20. 

17. Measure voltage between PCM connector terminal A5 and body ground. 

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

me 

 

Friday, June 05, 2009 2:34:58 PM

Page 13 

© 2005 Mitchell Repair Information Company, LLC.