DTC Troubleshooting: P050B
DTC P050B: Cold Start Ignition Timing Control System Performance Problem
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P050B Cold Start Ignition Timing Control System Performance Problem
      

1.
PGM-FI system check:

PGM-FI system check
?1.
Turn the vehicle to the ON mode.

?2.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
       

Are any Pending or Confirmed DTCs other than P050B indicated?

     
YES
     
     
     
Go to the indicated DTC's troubleshooting.?
     
NO
     
     
     
Go to step 2.
2.
Intake air duct visual check:

Intake air duct visual check
?1.
Check for a poor connection or blockage at the intake air duct.

Is it OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Reconnect or repair the intake air duct.?
3.
Air cleaner housing visual check:

Air cleaner housing visual check
?1.
Check for a poor connection or blockage at the air cleaner housing.

Is it OK?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
4.
Air cleaner element visual check:

Air cleaner element visual check
?1.
Check for dirt or debris on the air cleaner element.

Is it dirty?

     
YES
     
     
     
     
NO
     
     
     
Go to step 5.
5.
Problem verification:

Problem verification
?1.
Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.
Signal
Current conditions
Values
Unit
ECT SENSOR 1
    

?2.
Clear the DTC with the HDS.


?3.
Start the engine, and let it idle for 10 seconds or more.

?4.
Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P050B Cold Start Ignition Timing Control System Performance Problem
  

Does the HDS indicate FAILED?

     
YES
     
     
     
The failure is duplicated. Go to step 6.
     
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 PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 5-1 and recheck.
6.
Determine possible failure area (CKP sensor, others):

Determine possible failure area (CKP sensor, others)
?1.
Check the ignition timing.

Is the ignition timing OK?

     
YES
     
     
     
Go to step 8.
     
NO
     
     
     
Go to step 7.
7.
CKP sensor and CKP pulse plate visual check:

CKP sensor and CKP pulse plate visual check
?1.
Check for damage at the CKP sensor and the CKP pulse plate.

Is the CKP sensor and CKP pulse plate damaged?

     
YES
     
     
     
     
NO
     
     
     
The CKP sensor and the CKP pulse plate are OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck.
8.
Throttle body test:

Throttle body test
?1.
Select the ETCS TEST in the INSPECTION MENU with the HDS.

  

Is the THROTTLE ACTUATOR CONTROL VALVE normal?

     
YES
     
     
     
Go to step 9.
     
NO
     
     
     
9.
MAF sensor performance check:

MAF sensor performance check
?1.
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.

?2.
While holding the engine speed at 2,500 rpm for 30 seconds, check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
MAF SENSOR
6.5?9.2
g/s
    

Do the current condition(s) match the malfunction threshold?

     
YES
     
     
     
The MAF sensor is OK. Go to step 10.
     
NO
     
     
     
10.
ECT sensor 1 and ECT sensor 2 performance check:

ECT sensor 1 and ECT sensor 2 performance check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Allow the engine to cool to ambient temperature.

?3.
Note the ambient temperature.

?4.
Turn the vehicle to the ON mode.

?5.
Quickly note the value of the ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
ECT SENSOR 2
    

?6.
Compare the value of ECT SENSOR 1 and the value of ECT SENSOR 2 with 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.?
     
NO
     
     
     
The ECT sensors are OK. Check and repair any problems with the following items. Repair or replace them if needed. If every item is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM.?
Engine compression and cylinder leakdown
Engine oil
A/C system