P050B
DTC P050B: Cold Start Ignition Timing PerformanceNOTE: 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 P050B 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 25.
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 25.
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 25.
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 P050B 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. Inspect the ignition timing.
Is the ignition timing OK?
YES - Go to step 12.
NO - Go to step 11.
11. Check for damage at the CKP sensor and the CKP sensor pulsar plate.
Is the CKP sensor and/or the CKP sensor pulsar plate damaged?
YES - Replace the CKP sensor and/or the CKP sensor pulsar plate, then go to step 6.
NO - Go to step 31.
12. Do the ETCS TEST in the INSPECTION MENU with the HDS.
Is the THROTTLE ACTUATOR CONTROL VALVE normal?
YES - Go to step 13.
NO - Replace the throttle body, then go to step 25.
13. 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.
14. 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.
15. 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 16.
NO - Replace the MAF sensor/IAT sensor, then go to step 25.
16. Turn the ignition switch OFF.
17. Drain the coolant.
18. Remove ECT sensor 1, and ECT sensor 2.
19. Allow the sensors to cool to ambient temperature.
20. Note the ambient temperature.
21. Connect ECT sensor 1 to its 2P connector, and ECT sensor 2 to its 2P connector, but do not install them on the engine.
22. Turn the ignition switch ON (II).
23. Note the value of ECT SENSOR 1 and ECT SENSOR 2 quickly in the DATA LIST with the HDS.
24. Compare the value of ECT SENSOR 1 and the ambient temperature, and the value of ECT SENSOR 2 and the ambient temperature individually.
Does either sensor differ more than 5.4 degrees F (3 degrees C) from the ambient temperature?
YES - Replace the sensor that differed more than 5.4 degrees F (3 degrees C) from the ambient temperature, then go to step 25.
NO - Check and repair any problems with the following items, then go to step 25.
- Engine compression and cylinder leakdown
- VTEC system
- Engine oil
- A/C system
- Power steering
25. Turn the ignition switch ON (II).
26. Reset the ECM with the HDS.
27. Let the engine cool until the value of ECT SENSOR 1 is 122 degrees F (50 C) more or less.
28. Do the ECM idle learn procedure.
29. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC P050B is indicated, check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, 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 30.
30. Monitor the OBD STATUS for DTC P050B 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 CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, 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 27 and recheck.
31. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
32. Let the engine cool until the value of ECT SENSOR 1 is 122 degrees F (50 degrees C) or less.
33. Do the ECM idle learn procedure.
34. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P050B indicated?
YES - Check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the ECM. If the ECM was updated, substitute a known-good ECM, then go to step 32. If the ECM was substituted, go to step 1.
NO - If no Temporary DTCs or DTCs are indicated, go to step 35. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
35. Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the ECM. If the ECM was updated, substitute a known-good ECM, then go to STEP 32. If the ECM was substituted, go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 32 and recheck.