DTC Troubleshooting
DTC Troubleshooting: P050B
DTC P050B: Cold Start Ignition Timing Control System Performance Problem
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview
1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
2. Check for Pending or Confirmed DTCs with the HDS.
Are any Pending or Confirmed DTCs other than P050B indicated?
YES - Go to the indicated DTC's troubleshooting.
NO - Go to step 3.
3. Check for poor connections or a blockage at the intake air duct.
Is it OK?
YES - Go to step 4.
NO - Correct the problem, then reconnect the intake air duct, and 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, Service and Repair 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, Service and Repair then go to step 25.
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 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. 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 PCM. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 6.
10. Inspect the ignition timing. Testing and Inspection
Is the ignition timing OK?
YES - Go to step 12.
NO - Go to step 11.
11. Check for damage at the CKP sensor CKP Sensor Replacement and the CKP sensor pulse plate. CKP Pulse Plate Replacement
Is the CKP sensor and/or the CKP sensor pulse plate damaged?
YES - Replace the CKP sensor CKP Sensor Replacement and/or the CKP sensor pulse plate, CKP Pulse Plate Replacement then go to step 25.
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, Removal and Replacement then go to step 25.
13. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
14. 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.
15. While holding the engine speed at 2,500 rpm, check the MAF SENSOR in the DATA LIST with the HDS.
Is there about 11.0-15.5 gm/s (J35Z6 engine) or 11.8-16.6 gm/s (J37A4 engine)?
YES - Go to step 16.
NO - Replace the MAF sensor/IAT sensor, Service and Repair then go to step 25.
16. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
17. Drain the coolant. Service and Repair
18. Remove ECT sensor 1, ECT Sensor 1 Replacement and ECT sensor 2. ECT Sensor 2 Replacement
19. Allow the sensors to cool to the ambient temperature.
20. Note the ambient temperature.
21. Connect ECT sensor 1 and ECT sensor 2 to their 2P connectors, but do not install them.
22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
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 °F (3 °C) from the ambient temperature?
YES - Replace the sensor that differed more than 5.4 °F (3 °C) from the ambient temperature, then go to step 25.
NO - Check and repair any problems with the following items. Repair or replace them if needed, then go to step 25. If all of the items are OK, go to step 32.
- Engine compression and cylinder leak down
- VTEC system
- Engine oil
- A/C system
- Power steering
25. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
26. Reset the PCM with the HDS.
27. Do the PCM idle learn procedure. PCM Idle Learn Procedure
28. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.
29. Start the engine, and let it idle for 10 seconds or more.
30. Check for Pending or Confirmed 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 PCM, then go to step 1.
NO - Go to step 31.
31. Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 30, go to the indicated DTC's troubleshooting.
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 PCM, 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 28.
32. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Initial Inspection and Diagnostic Overview
33. Do the PCM idle learn procedure. PCM Idle Learn Procedure
34. Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.
35. Start the engine, and let it idle for 10 seconds or more.
36. Check for Pending or Confirmed 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 PCM. If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then go to step 34. If the PCM was substituted, go to step 1.
NO - Go to step 37.
37. Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. PCM Replacement If any other Pending or Confirmed DTCs were indicated in step 36, go to the indicated DTC's troubleshooting.
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 PCM. If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then go to step 34. If the PCM was substituted, 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 34.