DTC Troubleshooting: P050B (L4: KA/KC) - Honda Accord CR/CT 2012-2017

DTC Troubleshooting: P050B

DTC P050B: Cold Start Ignition Timing Control System Performance Problem

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

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

PGM-FI system check:

PGM-FI system check

?1.	Turn the ignition switch to ON (II), or press the engine start/stop button to select 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.

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, then do the repair verification.

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

Replace the air cleaner housing, then do the repair verification.

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

Replace the air cleaner element, then do the repair verification.


	NO

Go to step 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
Signal	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/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.

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.

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

Replace the CKP sensor and/or the CKP pulse plate, then do the repair verification.


	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 do the repair verification.

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

Replace the throttle body, then do the repair verification.

MAF sensor performance check:

MAF sensor performance check

?1.	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.

?2.

While holding the engine speed at 2,500 rpm for 30 seconds, check the parameter(s) below with the HDS.

A/T

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
MAF SENSOR	6.5?9.1	g/s

M/T

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
MAF SENSOR	5.5?7.7	g/s

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


	YES

The MAF sensor is OK. Go to step 10.


	NO

Replace the MAF sensor/IAT sensor, then do the repair verification.

10.

ECT sensor 1 and ECT sensor 2 performance check:

ECT sensor 1 and ECT sensor 2 performance check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

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

?3.	Note the ambient temperature.

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select 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
Signal	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, then do the repair verification.


	NO

The ECT sensors are OK. Check and repair any problems with the following items. Repair or replace them if needed, then do the repair verification. If every item is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.

	Engine compression and cylinder leakdown
	Valve pause system
	Engine oil
	A/C system

Repair verification (OBD STATUS check):

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect all connectors.

?3.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.	Reset the PCM with the HDS.

?5.	Do the PCM idle learn procedure.

?6.

Let the engine cool until the value of ECT SENSOR 1 is 122 °F (50 °C) or less.

Signal	Current conditions
Signal	Values	Unit
ECT SENSOR 1

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

?8.

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 PASSED, FAILED, EXECUTING, or OUT OF CONDITION?


	PASSED

Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?


	FAILED

Go to step 1 and recheck. if the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.


	EXECUTING

Keep idling until a result comes on


	OUT OF CONDITION

Meet the test condition, and check the OBD STATUS again.