DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: 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 How To Troubleshoot The Fuel And Emissions Systems.

1. PGM-FI system check:

PGM-FI system check
-1. Turn the ignition switch to ON (II).

-2. Check for Pending or Confirmed DTCs with the HDS.

Are any Pending or Confirmed DTCs other than P050A indicated?
-YES- Go to the indicated DTC's troubleshooting.
-NO- Go to step 2.

2. Intake air duct visual check:

Intake air duct visual check
-1. Check for a poor connection or blockage at the intake air duct.

Is it OK?
-YES- Go to step 3.
-NO- Reconnect or repair the intake air duct, then do the repair verification.

3. Air cleaner housing visual check:

Air cleaner housing visual check
-1. Check for a poor connection or blockage at the air cleaner housing.

Is OK?
-YES- Go to step 4.
-NO- Replace the air cleaner housing Service and Repair, then do the repair verification.

4. Air cleaner element visual check:

Air cleaner element visual check
-1. Check for dirt or debris on the air cleaner element.

Is it dirty?
-YES- Replace the air cleaner element Service and Repair, then do the repair verification.
-NO- Go to step 5.

5. Problem verification:

Problem verification
-1. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.

-2. Clear the DTC with the HDS.

-3. Start the engine, and let it idle for 10 seconds or more.

-4. Monitor the OBD STATUS for DTC P050A with the HDS.

Does the HDS indicate FAILED?
-YES- The failure is duplicated. Go to step 6.
-NO- If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and the ECM/PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 5-1. and recheck.

6. Throttle body test:

Throttle body test
-1. Do the ETCS TEST with the HDS.

Is the THROTTLE ACTUATOR CONTROL VALVE normal?
-YES- Go to step 7.
-NO- Replace the throttle body Removal and Replacement, then do the repair verification.

7. MAF sensor performance check:

MAF sensor performance check
-1. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

-2. While holding the engine speed at 2,500 rpm for 30 seconds, check the MAF SENSOR in the DATA LIST with the HDS.

Is there about 5.3-6.5 g/s
-YES- The MAF sensor is OK. Go to step 8.
-NO- Replace the MAF sensor/IAT sensor Service and Repair, then do the repair verification.

8. IAT sensor performance check:

IAT sensor performance check
-1. Turn the ignition switch to LOCK (0).

-2. Allow the engine to cool to ambient temperature.

-3. Note the ambient temperature.

-4. Turn the ignition switch to ON (II).

-5. Quickly note the value of the IAT SENSOR in the DATA LIST with the HDS.

-6. Compare the value of the IAT SENSOR with the ambient temperature.

Does the value of the IAT SENSOR differ 5.4 °F (3 °C) or more from the ambient temperature?
-YES- Replace the MAF sensor/IAT sensor Service and Repair, then do the repair verification.
-NO- The IAT sensor is OK. Check for dirt, carbon, or damage in the throttle bore. If there is dirt or carbon, clean the throttle body Throttle Body Cleaning, then do the repair verification. If there is damage in the throttle bore, replace the throttle body Removal and Replacement, then do the repair verification.

Repair verification (OBD STATUS check):

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM/PCM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.

-6. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.

-7. Start the engine, and let it idle for 10 seconds or more.

-8. Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, EXECUTING, or OUT OF CONDITION?
-PASSED- Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck.
-EXECUTING- Keep the test condition until a result comes on.
-OUT OF CONDITION- Meet the test condition, and check the OBD STATUS again.