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
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
     

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.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for 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, or replace it if needed.?
3.
Air cleaner housing visual check:

Air cleaner housing visual check
?1.
Check for 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.
Turn the vehicle to the ON mode.

?2.
Let the engine cool until the value of ECT SENSOR 1 is 77 °F (25 °C) or less.
Signal
Current conditions
Values
Unit
ECT SENSOR 1
    

?3.
Clear the DTC with the HDS.


?4.
Turn the vehicle to the OFF (LOCK) mode.

?5.
Start the engine, and let it idle for 10 seconds or more.

?6.
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, MAF/IAT sensor 1, ECT sensor 1, ECT sensor 2, and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 5-2 and recheck.?
6.
MAF sensor performance check:

MAF sensor performance check
?1.
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
4.1?5.7
g/s
    

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

     
YES
     
     
     
The MAF sensor is OK. Go to step 7.
     
NO
     
     
     
7.
IAT sensor 1 performance check:

IAT sensor 1 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 IAT SENSOR (1) in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
IAT SENSOR (1)
    

?6.
Compare the value of the IAT SENSOR (1) with the ambient temperature.

Does the value of the IAT SENSOR (1) differ 5.4 °F (3 °C) or more from the ambient temperature?

     
YES
     
     
     
     
NO
     
     
     
IAT sensor 1 is OK. Check for dirt, carbon, or damage in the throttle bore. If there is dirt or carbon, clean the throttle body. If there is damage in the throttle bore, replace the throttle body.?