DTC P0101: Mass Air Flow Circuit Range / Performance Problem: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.
   RESULT
   
   

   Result	Proceed to
   DTC P0101 is output	A
   DTC P0101 and other DTCs are output	B

   HINT: 

   If any DTCs other than P0101 are output, troubleshoot those DTCs first.

B → See step   8 

A: Go to next step 

1. Check the intake system for vacuum leaks. Refer to ON-VEHICLE INSPECTION .

   OK

   No leaks from intake system.

NG → REPAIR OR REPLACE INTAKE SYSTEM 

OK: Go to next step 

1. Check the PCV hose connections. Refer to COMPONENTS .

   OK

   PCV valve and hose are connected correctly and are not damaged.

NG → REPAIR OR REPLACE PCV HOSE 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE .
5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

   HINT: 

   The A/C switch and all accessory switches should be off.

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Primary / MAP.
7. Check the engine idling condition and MAP values in the Data List while performing the Active Test.

   HINT: 

   • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
   • Be sure to return the EGR valve to step 0 when the Active Test is completed.
   • Do not open the EGR valve 30 steps or more during the Active Test.

   OK

   MAP and idling condition change in response to EGR step position.

   Standard

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling or engine stalls
   MAP (Data List)	MAP value is 20 to 40 kPa(abs) [150 to 300 mmHg(abs)] (EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

   HINT: 

   During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

   RESULT
   
   

   Result	Proceed to
   Outside of standard range	A
   Within standard range	B

B → See step   6 

A: Go to next step 

1. Remove the EGR valve assembly. Refer to REMOVAL .
2. Check if the EGR valve is stuck open.

   OK

   EGR valve is tightly closed.

NG → See step   9 

OK: Go to next step 

1. Replace the mass air flow meter sub-assembly. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR .
5. Turn the power switch off and wait for at least 30 seconds.
6. Turn the power switch on (IG).
7. Turn the Techstream on.
8. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE .
9. Start the engine and warm it up.
10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
12. Input the DTC: P0101.
13. Check the DTC judgment.
    RESULT
    
    

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

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