DTC P050A: Cold Start Idle Air Control System Performance (TO 12/2010): Procedure

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)

Connect Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Select the following the menu items: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Result

Result	Proceed to
DTC P050A is output	A
DTC P050A and other DTCs are output	B

HINT:

If any DTCs other than P050A are output, troubleshoot those DTCs first.

B → See step 20

A: Go to next step

READ VALUE USING TECHSTREAM (FUEL TRIM)
HINT:

Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.
1. Connect Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Select the following menu items: Powertrain / Engine / Data List / All Data / Short FT #1 and Long FT #1 or Short FT #2 and Long FT #2.
5. Read the values displayed on the Techstream.
6. Add together the Short FT #1 and Long FT #1 or Short FT #2 and Long FT #2 values to obtain the total fuel trim.
  OK
  
  Total of Short FT #1 and Long FT #1 or Short FT #2 and Long FT #2 values is between -20% and 20%.
NG → See step 5

OK: Go to next step
INSPECT THROTTLE BODY ASSEMBLY
1. Check for deposits around the throttle valve and check the throttle valve condition.
  OK
  
  No deposits around the throttle valve and throttle valve moves smoothly.
OK → See step 14

NG → See step 4
REPAIR OR REPLACE THROTTLE BODY ASSEMBLY
1. Repair or replace the throttle body assembly. Refer to REMOVAL .
NEXT → See step 14
CHECK PCV SYSTEM
1. Check the PCV hose connections.
  OK
  
  PCV hose is connected correctly and is not damaged.
NG → See step 10

OK: Go to next step
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leaks.
  OK
  
  No leakage from the air induction system.
NG → See step 11

OK: Go to next step
CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
1. Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.
  OK
  
  Air cleaner filter element is not excessively contaminated with dirt or oil.
NG → See step 12

OK: Go to next step

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT SYSTEM)

Connect Techstream to the DLC3.
Start the engine and turn the Techstream ON.
Select the following menu items: Powertrain / Engine / Active Test / Control the VVT System (Bank1) and Control the VVT System (Bank2).

Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.

Techstream Operation	Specified Condition
OFF	Normal engine speed
ON	Engine idles roughly or stalls (soon after OCV switched from OFF to ON)

NG → See step 13

OK: Go to next step

READ VALUE USING TECHSTREAM (MAF)
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Data List / All Data / MAF and Coolant Temp.
5. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
6. Read MAF with the engine speed at 3000 RPM.
  Standard
  
  Between 12 g/sec. and 17 g/sec. (shift lever: N; A/C: Off).
OK → See step 14

NG → See step 15
REPAIR OR REPLACE PCV HOSE
1. Repair or replace the PCV hose.
NEXT → See step 14
REPAIR OR REPLACE AIR INDUCTION SYSTEM
1. Repair or replace the air induction system.
NEXT → See step 14
REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
1. Replace the air cleaner filter element sub-assembly.
NEXT → See step 14
CHECK AND REPAIR VVT SYSTEM
1. Check and repair the VVT system.
NEXT: Go to next step

CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)

NOTE:

In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).

Connect Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs. Refer to DTC CHECK / CLEAR .
Turn the ignition switch off.
Turn the ignition switch to ON and turn the Techstream on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

Read the pending DTCs.

Result

Result	Proceed to
DTC is not output	A
DTC P050A is output	B

B → See step 15

A → See step 22

CHECK HARNESS AND CONNECTOR
1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE .
  HINT:
  
  Repair any problems.
NEXT: Go to next step

CHECK WHETHER DTC OUTPUT RECURS

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs. Refer to DTC CHECK / CLEAR .
Turn the ignition switch off.
Turn the ignition switch to ON and turn the Techstream on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

Read the pending DTCs.

RESULT

Result	Proceed to
DTC P050A is output	A
DTC is not output	B

B → END

A: Go to next step

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

Disconnect the mass air flow meter connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
B50-72 (VG) - B10-5 (VG)	Always	Below 1 Ω
B50-73 (E2G) - B10-4 (E2G)	Always	Below 1 Ω
B50-72 (VG) or B10-5 (VG) - Body ground	Always	10 kΩ or higher

Reconnect the mass air flow meter connector.
Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

REPLACE MASS AIR FLOW METER
1. Replace the mass air flow meter.
  HINT:
  
  If the result of the inspection performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter.
NEXT: Go to next step

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

NOTE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs. Refer to DTC CHECK / CLEAR .
Turn the ignition switch off.
Turn the ignition switch to ON and turn the Techstream on.
Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

Read the pending DTCs.

RESULT

Result	Proceed to
DTC is not output	A
DTC P050A is output	B

B → See step 21

A → END

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART
REPLACE ECM. Refer to REMOVAL
CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS