FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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P050A

DTC P050A: Cold Start Idle Air Control System Performance Problem

NOTE: 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 DTC's 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 degrees F (50 degrees C) or less.
7. Clear the DTC with the HDS.
8. Start the engine, and let it idle 10 seconds or more.
9. Monitor the OBD STATUS for DTC P050 A 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, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, go to step 6 and recheck.

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 ENG 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 6.0-8.6 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 degrees F (3 degrees 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. Let the engine cool until the value of ECT SENSOR 1 is 122 degrees F (50 degrees C) or less.
23. Do the ECM idle learn procedure.
24. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P050A is indicated, 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 any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Go to step 25.

25. Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

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, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, go to step 20 and recheck.