DTC P050B: Cold Start Ignition Timing Control System Performance Problem
- Turn the ignition switch to ON (II).
- 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.
- Check for a blocked or an incorrectly installed intake air duct.
Is it OK?
YES -Go to step 4.
NO -Reconnect or repair the intake air duct, then go to step 21.
- 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 ELEMENT INSPECTION/REPLACEMENT ), then go to step 21.
- Check for dirt or debris in the air cleaner element.
Is it dirty?
YES -Replace the air cleaner element or remove the debris (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), then go to step 21.
NO -Go to step 6.
- Let the engine cool until the value of ECT SENSOR 1 is 122°F (50°C) or less.
- Clear the DTC with the HDS.
- Start the engine, and let it idle for 10 seconds or more.
- Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the HDS indicate FAILED?
YES -Go to step 10.
NO -If the HDS 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 ECM/PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 6.
- Inspect the ignition timing (see
IGNITION TIMING INSPECTION
).
Is the ignition timing OK?
YES -Go to step 12.
NO -Go to step 11.
- Check for damage at the CKP sensor (see CKP SENSOR REPLACEMENT
) and the CKP sensor pulse plate (see
CKP PULSE PLATE REPLACEMENT
).
Is the CKP sensor or the CKP sensor pulse plate damaged?
YES -Replace the CKP sensor (see CKP SENSOR REPLACEMENT ) and/or the CKP sensor pulse plate (see CKP PULSE PLATE REPLACEMENT ), then go to step 21.
NO -Go to step 28.
- 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 (see THROTTLE BODY REMOVAL/INSTALLATION ), then go to step 21.
- Start the engine. Hold the engine speed at 3, 000 RPM without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
- 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 4.7-5.7 gm/s (CVT) or 4.5-5.5 gm/s (M/T)?
YES -Go to step 15.
NO -Replace the MAF sensor/IAT sensor (see MAF SENSOR/IAT SENSOR REPLACEMENT ), then go to step 21.
- Turn the ignition switch to LOCK (0).
- Allow the ECT sensors to cool to the ambient temperature.
- Note the ambient temperature.
- Turn the ignition switch to ON (II).
- Quickly note the value of ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
- 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 21.
NO -Check and repair any problems with the following items. Repair or replace them if needed, then go to step 21.
- Engine compression and cylinder leakdown
- VTEC system
- Engine oil
- A/C system
- Power steering
- Turn the ignition switch to ON (II).
- Reset the ECM/PCM with the HDS.
- Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
- Let the engine cool until the value of ECT SENSOR 1 is 122°F (50°C) or less.
- Start the engine, and let it idle for 10 seconds or more.
- 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 ECM/PCM, then go to step 1.
NO -Go to step 27.
- Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?
YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 26, go to the indicated DTC'S TROUBLESHOOTING .
NO -If the HDS 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 HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 24.
- Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
- Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
- Let the engine cool until the value of ECT SENSOR 1 is 122°F (50°C) or less.
- Start the engine, and let it idle for 10 seconds or more.
- 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 ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 30. If the ECM/PCM was substituted, go to step 1.
NO -Go to step 33.
- Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
Does the HDS 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 Pending or Confirmed DTCs were indicated in step 32, go to the indicated DTC'S TROUBLESHOOTING .
NO -If the HDS 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. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 30. If the ECM/PCM was substituted, go to step 1. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 30.