DTC Troubleshooting: P1519 (14-3)

DTC P1519 (14-3):  IAC Valve Circuit Malfunction

1.Reset the ECM/PCM.

2.Turn the ignition switch ON (II).

Is DTC P1519 indicated?


YES - Go to 3.


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


3.Turn the ignition switch OFF.

4.Disconnect the IAC valve 3P connector.

5.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Go to 7.


NO - Repair open in the wire between the IAC valve and the PGM-FI main relay.n


7.Turn the ignition switch OFF.

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

 

Is there continuity?


YES - Go to 9.


NO - Repair open in the wire between the IAC valve and G101.n


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

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

 

Is there continuity?


YES - Repair short in the wire between the IAC valve and the ECM/PCM (A12).n


NO - Go to 11.

11.Connect the IAC valve 3P connector terminal No. 3 and body ground with a jumper wire.

 


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

 

Is there continuity?


YES - Go to 13.


NO - Repair open in the wire between the IAC valve and the ECM/PCM (A12).n


13.Reconnect the IAC valve 3P connector.

14.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


NO - Replace the IAC valve.n