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 poor connections or a blockage at the intake air duct.
Is it OK?
YES: Go to step 4.
NO: Reconnect or repair the intake air duct, then go to step 24.
- 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 24.
- 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 24.
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 screen indicate FAILED?
YES: Go to step 10.
NO: If the HDS indicates PASSED, intermittent failure, the system is OK at this time. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION or NOT COMPLETED, 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 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 25.
NO: Go to step 31.
- 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 24.
- 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.
- 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 4.6 - 5.7 gm/s (M/T) or 4.7-5.7 gm/s (A/T)?
YES: Go to step 15.
NO: Replace the MAF sensor/IAT sensor (see MAF SENSOR/IAT SENSOR REPLACEMENT ), then go to step 24.
- Turn the ignition switch to LOCK (0).
- Drain the coolant (see COOLANT CHECK ).
- Remove ECT sensor 1 (see ECT SENSOR 1 REPLACEMENT ), and ECT sensor 2 (see ECT SENSOR 1 REPLACEMENT ).
- Allow the sensors to cool to the ambient temperature.
- Note the ambient temperature.
- Connect ECT sensor 1 and ECT sensor 2 to their 2P connectors, but do not install them.
- Turn the ignition switch to ON (II).
- Note the value of ECT SENSOR 1 and ECT SENSOR 2 quickly 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 24.
NO: Refill the coolant (see COOLANT CHECK ), then check for and repair any problems with the following items. If the items are OK, go to step 24.
- 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 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 30.
- 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 29, 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 or NOT COMPLETED, go to step 27.
- 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 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 33. If the ECM/PCM was substituted, go to step 1.
NO: Go to step 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 Pending or Confirmed DTCs were indicated in step 35, 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 33. 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 or NOT COMPLETED, go to step 33.