LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2009 >> CSX Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P050B: Cold Start Ignition Timing Control System Performance Problem
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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 (see 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 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  25.

  4. Check for damage at the air cleaner housing.

    Is it OK? 

    YES  -Go to step 5.

    NO  -Replace the air cleaner housing (see AIR CLEANER REMOVAL/INSTALLATION ), 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 debris (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), then go to step  25.

    NO  -Go to step 6.

  6. Let the engine cool until the value of ECT SENSOR 1 is 50°C (122°F) 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, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step  6.

  10. Inspect the ignition timing (see IGNITION TIMING INSPECTION ).

    Is the ignition timing OK? 

    YES  -Go to step  12.

    NO  -Go to step 11.

  11. Check for damage at the CKP sensor (see CKP SENSOR REPLACEMENT  ) and the CKP sensor pulser plate (see CKP PULSE PLATE REPLACEMENT ).

    Is the CKP sensor and/or the CKP sensor pulser plate damaged? 

    YES  -Replace the CKP sensor (see CKP SENSOR REPLACEMENT  ) and/or the CKP sensor pulser plate (see CKP PULSE PLATE REPLACEMENT ), 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; K20Z2 engine (see THROTTLE BODY REMOVAL/INSTALLATION ), K20Z3 engine (see K20Z3 ENGINE ), then go to step  25.

  13. Start the engine. Hold the engine speed at 3,000 rpm (min-1 ) without load (in Park or neutral) 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 (min-1 ) for at least 30 seconds.
  15. While holding the engine speed at 2,500 rpm (min-1 ), check the MAF SENSOR in the DATA LIST with the HDS.

    Is there about 6-8.6 (K20Z2 engine) or 5.7-8.3 (K20Z3 engine) gm/s? 

    YES  -Go to step 16.

    NO  -Replace the MAF sensor/IAT sensor (see MAF SENSOR/IAT SENSOR REPLACEMENT  ), then go to step  25.

  16. Turn the ignition switch OFF.
  17. Drain the coolant (see COOLANT CHECK ).
  18. Remove ECT sensor 1 (see ECT SENSOR 1 REPLACEMENT  ), and ECT sensor 2 (see ECT SENSOR 1 REPLACEMENT  ).
  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 3°C (5.4°F) from the ambient temperature? 

    YES  -Replace the sensor that differed more than 3°C (5.4°F) 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/PCM with the HDS.
  27. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  28. Let the engine cool until the value of ECT SENSOR 1 is 50°C (122°F) or less.
  29. Start the engine, and let it idle 10 seconds or more.
  30. 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/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 Temporary DTCs or DTCs were indicated in step  30, go to the INDICATED DTCS 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 ECM/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 ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
  33. Let the engine cool until the value of ECT SENSOR 1 is 50°C (122°F) or less.
  34. Start the engine, and let it idle 10 seconds or more.
  35. 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/IAT sensor, ECT sensor 1, ECT sensor 2, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  33. If the ECM/PCM was substituted, go to step  1.

    NO  -Go to step 36.

  36. Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.

    Does the screen indicate PASSED? 

    YES  -If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT  ). If any other Temporary DTCs or DTCs were indicated in step  35, go to the INDICATED DTCS TROUBLESHOOTING .

    NO  -If the screen indicates FAILED, check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF/IAT sensor, ECT sensor 1, ECT sensor 2, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  33. If the ECM/PCM 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  33.

scientia non olet · About LEMON Manuals