DTC Troubleshooting
DTC P050A: Cold Start Idle Air Control System Performance ProblemNOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
1. Turn the ignition switch ON (II).
2. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs other than P050A indicated?
YES - Go to the indicated DTCs troubleshooting.
NO - Go to step 3.
3. Check for poor connections or blockage at the air intake duct.
Is it OK?
YES - Go to step 4.
NO - Reconnect or repair the air intake duct, then go to step 20.
4. Check for damage at the air cleaner housing.
Is it OK?
YES - Go to step 5.
NO - Replace the air cleaner housing, then go to step 20.
5. Check for dirt or debris in the air cleaner element.
Is it dirty?
YES - Replace the air cleaner element or remove the debris, then go to step 20.
NO - Go to step 6.
6. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 "C) or less.
7. Clear the DTC with the HDS.
8. Start the engine, and let it idle for 10 seconds or more.
9. Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 10.
NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 6.
10. Do the ETCS TEST in the INSPECTION MENU with the HDS.
Is the THROTTLE ACTUATOR CONTROL VALVE normal?
YES - Go to step 11.
NO - Replace the throttle body, then go to step 20.
11. Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.
12. Monitor the ENGINE SPEED in the DATA LIST with the HDS, and hold the engine speed at 2,500 rpm for at least 30 seconds.
13. While holding the engine speed at 2,500 rpm, check the MAF SENSOR in the DATA LIST with the HDS.
Is there about 5.7-8.3 gm/s?
YES - Go to step 14.
NO - Replace the MAF sensor/IAT sensor, then go to step 20.
14. Turn the ignition switch OFF.
15. Allow the engine to cool to ambient temperature.
16. Note the ambient temperature.
17. Turn the ignition switch ON (II).
18. Note the value of IAT SENSOR quickly in the DATA LIST with the HDS.
19. Compare the value of the IAT SENSOR and the ambient temperature.
Does the value of the IAT SENSOR differ 5.4 °F (3 °C) or more?
YES - Replace the MAF sensor/IAT sensor, then go to step 20.
NO - Check for dirt, carbon, or damage in the throttle bore. If there is dirt or carbon, clean the throttle body, then go to step 20. If there is damage in the throttle bore, replace the throttle body, then go to step 20.
20. Turn the ignition switch ON (II).
21. Reset the ECM with the HDS.
22. Do the ECM idle learn procedure.
23. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.
24. Start the engine, and let it idle for 10 seconds or more.
25. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P050A indicated?
YES - Check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and the ECM, then go to step 1.
NO - Go to step 26.
26. Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 25, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and the ECM, then go to step 1. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 23.