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Home >> Suzuki >> 2009 >> Equator Base, 4D Pickup >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (VQ40DE) - (3 Of 5) >> DTC P2a00, P2a03: A/F Sensor 1 >> Diagnosis Procedure
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Diagnosis Procedure

DIAGNOSIS PROCEDURE

Step Action YES NO
1  CHECK GROUND CONNECTIONS 
  1. Turn ignition switch OFF.
  2. Loosen and retighten three ground screws on the body. Refer to [POWER SUPPLY AND GROUND CIRCUIT CHECK ].
G06441639Courtesy of SUZUKI OF AMERICA CORP.

OK or NG 		 GO TO 2. Repair or replace ground connections.
2  RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1 
Loosen and retighten the air fuel ratio (A/F) sensor 1. Refer to [EXHAUST MANIFOLD AND THREE WAY CATALYST: REMOVAL AND INSTALLATION [VQ40DE] ]		 GO TO 3.  
3  CHECK FOR INTAKE AIR LEAK 
  1. Start engine and run it at idle.
  2. Listen for an intake air leak after the mass air flow sensor.

OK or NG 		 GO TO 4. Repair or replace.
4  CLEAR THE SELF-LEARNING DATA. 
  1. With SDT 
    1. Start engine and warm it up to normal operating temperature.
    2. Select "SELF-LEARNING CONT" in "Utility" mode with SDT.
    3. Clear the self-learning control coefficient by touching "Clear".
    4. Run engine for at least 10 minutes at idle speed.

      Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine? 

  2. Without SDT 
    1. Start engine and warm it up to normal operating temperature.
    2. Turn ignition switch OFF.
    3. Disconnect mass air flow sensor harness connector.
G06441640Courtesy of SUZUKI OF AMERICA CORP.

  1. 4. Restart engine and let it idle for at least 3 seconds.
  2. 5. Stop engine and reconnect mass air flow sensor harness connector.
  3. 6. Make sure DTC P0102 is displayed.
  4. 7. Erase the DTC memory. Refer to [EMISSION-RELATED DIAGNOSTIC INFORMATION ].
  5. 8. Make sure DTC P0000 is displayed.
  6. 9. Run engine for at least 10 minutes at idle speed.

    Is the 1st trip DTC P0171, P0172 or P0174, P0175 detected? 

    Is it difficult to start engine? 


Yes or No 		 Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to or . GO TO 5.
5  CHECK HARNESS CONNECTOR 
  1. Turn ignition switch OFF.
  2. Disconnect A/F sensor 1 harness connector.
G06441641Courtesy of SUZUKI OF AMERICA CORP.

  1. 3. Check harness connector for water.

    Water should not exit. 


OK or NG 		 GO TO 6. Repair or replace harness connector.
6  CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT 
  1. Turn ignition switch ON.
  2. Check voltage between A/F sensor 1 terminal 4 and ground with SDT or tester.
G06441642Courtesy of SUZUKI OF AMERICA CORP.

Voltage: Battery voltage 


OK or NG 		 GO TO 8. GO TO 7.
7  DETECT MALFUNCTIONING PART 
Check the following.
  • Harness connectors E2, F32
  • IPDM E/R connector E119
  • 15 A fuse (No. 54)
  • Harness for open or short between A/F sensor 1 and fuse
 Repair or replace harness or connectors.  
8  CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT 
  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.

    Refer to WIRING DIAGRAM .

G06441643G06441644Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

Continuity should exist. 
  1. 4. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
G06441643G06441644Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

Continuity should not exist. 
  1. 5. Also check harness for short to ground and short to power.

OK or NG 		 GO TO 9. Repair open circuit or short to ground or short to power in harness or connectors.
9  CHECK A/F SENSOR 1 HEATER 
Refer to [P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER ].
OK or NG 		 GO TO 10. GO TO 11.
10  CHECK INTERMITTENT INCIDENT 
Perform [SERVICE INFORMATION FOR ELECTRICAL INCIDENT: INTERMITTENT INCIDENT ]
OK or NG 		 GO TO 11. Repair or replace.
11  REPLACE A/F SENSOR 1 
Replace malfunctioning A/F sensor 1.		 GO TO 12.  
12  CONFIRM A/F ADJUSTMENT DATA 
  1. Turn ignition switch ON.
  2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "Data list" mode with SDT.
  3. Make sure that "0" is displayed on SDT screen.

OK or NG 		 INSPECTION END  GO TO 13.
13  CREAR A/F ADJUSTMENT DATA 
With SDT 
  1. Start engine and warm it up to normal operating temperature.
  2. Select "SELF-LEARNING CONT" in "Utility" mode with SDT.
  3. Clear the self-learning control coefficient by touching "Clear".

Without SDT 
  1. Start engine and warm it up to normal operating temperature.
  2. Turn ignition switch OFF.
  3. Disconnect mass air flow sensor harness connector.
G06441645Courtesy of SUZUKI OF AMERICA CORP.

  1. 4. Restart engine and let it idle for at least 5 seconds.
  2. 5. Stop engine and reconnect mass air flow sensor harness connector.
  3. 6. Make sure DTC P0102 is displayed.
  4. 7. Erase the DTC memory. Refer to [EMISSION-RELATED DIAGNOSTIC INFORMATION ].
  5. 8. Make sure DTC P0000 is displayed.
 GO TO 14.  
14  CONFIRM A/F ADJUSTMENT DATA 
  1. Turn ignition switch OFF and then ON.
  2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "Data list" mode with SDT.
  3. Make sure that "0" is displayed on SDT screen.

OK or NG 		 INSPECTION END   
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