DTC Troubleshooting: P0511 (14)

DTC P0511:  IAC Valve Circuit Malfunction


1.Turn the ignition switch ON (II).

2.Do the DTC CLEAR in the CLEAR MENU with the Honda PGM Tester or the HDS.

3.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Is DTC P0511 indicated?


YES - Go to 4.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IAC valve and the  ECM/PCM.n


4.Turn the ignition switch OFF.

5.Disconnect the IAC valve 3P connector.

6.Turn the ignition switch ON (II).

7.Measure voltage between IAC valve 3P connector terminal No. 2 and body ground.

Is there battery voltage?


YES - Go to 8.


NO - Repair open in the wire between the IAC valve and the PGM-FI main relay 1 (FI-MAIN), then go to 22.



8.Turn the ignition switch OFF.

9.Check for continuity between body ground and IAC valve 3P connector terminal No. 1.

Is there continuity?


YES - Go to 10.


NO - Repair open in the wire between the IAC valve and G101, then go to 21.


10.Turn the ignition switch OFF.

11.Jump the SCS line with the Honda PGM Tester or the HDS.

12.Disconnect ECM/PCM connector A (31P).

13.Check for continuity between ECM/PCM connector terminal A12 and body ground.

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (A12) and the IAC valve, then go to 21.


NO - Go to 14.

14.Connect IAC valve 3P connector terminal No. 3 to body ground with a jumper wire.

15.Check for continuity between ECM/PCM connector terminal A12 and body ground.

Is there continuity?


YES - Go to 16.


NO - Repair open in the wire between the ECM/PCM (A12) and the IAC valve, then go to 21.


16.Reconnect the IAC valve 3P connector.

17.Turn the ignition switch ON (II).

18.Measure voltage between ECM/PCM connector terminal A12 and body ground.

Is there battery voltage?


YES - Go to 26.


NO - Go to 19.


19.Turn the ignition switch OFF.

20.Replace the IAC valve.

21.Turn the ignition switch ON (II).

22.Do the ECM/PCM RESET in the CLEAR MENU with the Honda PGM Tester or the HDS.

23.Do the ECM/PCM idle learn procedure.

24.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0511 is indicated, check for poor connections or loose terminals at the IAC valve and the  ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Go to 25.

25.Monitor the OBD STATUS for DTC P0511 in the DTCs MENU with the Honda PGM Tester or the HDS.

Is it PASSED?


YES - Troubleshooting is complete.n


NO - If it is FAILED, then go to 1. and recheck. If it is NOT COMPLETED, go to 23. and recheck.


26.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

27.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0511 is indicated, check for poor connections or loose terminals at the IAC valve and the  ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - If the  ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n