DTC P050B: Cold Start Ignition Timing Control System Performance Problem
- Turn the ignition switch to ON (II).
- 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.
- 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 25.
- 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 25.
- 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 25.
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 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 ECM/PCM. 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.
- Check 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 6.
NO -Go to step 32.
- 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 25.
- 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.
- 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.
- While holding the engine speed at 2,500 rpm, check the MAF SENSOR in the DATA LIST with the HDS.
Is there about 6.4- 9.2 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.
- 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 2 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 25.
NO -Check and repair any problems with the following items. Repair or replace parts as needed, then go to step 25. If all of the items are OK, go to step 32.
- 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 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.
- 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 29, 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.
- 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 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. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 34. If the ECM/PCM was substituted, go to step 1.
NO -Go to step 37.
- 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 36, 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. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 34. If the ECM/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.