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Home >> Suzuki >> 2009 >> Equator RMZ-4 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (VQ40DE) - (4 Of 5) >> DTC P0138, P0158: Ho2S2 >> Diagnosis Procedure >> Procedure For Malfunction A
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Procedure For Malfunction A

DIAGNOSIS PROCEDURE

Step Action YES NO
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 ].
G06441350Courtesy of SUZUKI OF AMERICA CORP.

OK or NG 
GO TO 2. Repair or replace ground connections.
CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT 
  1. Disconnect heated oxygen sensor 2 harness connector.
G06441351Courtesy of SUZUKI OF AMERICA CORP.

  1. 2. Disconnect ECM harness connector.
  2. 3. Check harness continuity between HO2S2 terminal 4 and ECM terminal 78.

    Refer to WIRING DIAGRAM .

    Continuity should exist. 

  3. 4. Also check harness for short to ground and short to power.

OK or NG 
GO TO 3. Repair open circuit or short to ground or short to power in harness or connectors.
CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
  1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.

    Refer to WIRING DIAGRAM .

G06441352G06441353Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

Continuity should exist. 
  1. 2. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
G06441352G06441353Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

Continuity should not exist. 
  1. 3. Also check harness for short to power.

OK or NG 
GO TO 4. Repair open circuit or short to ground or short to power in harness or connectors.
CHECK HO2S2 CONNECTOR FOR WATER 
Check connectors for water.
Water should not exist. 
OK or NG 
GO TO 5. Repair or replace harness or connectors.
CHECK HEATED OXYGEN SENSOR 2 
Refer to [P0138, P0158 HO2S2 ].
OK or NG 
GO TO 6. Replace malfunctioning heated oxygen sensor 2.
CHECK INTERMITTENT INCIDENT 
Refer to [SERVICE INFORMATION FOR ELECTRICAL INCIDENT: INTERMITTENT INCIDENT ]
INSPECTION END