LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2006 >> Forenza Base, 4D Wagon, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine Performance - DTC P0016 - P0141 >> DTC P0134: HO2S Circuit Insufficient Activity Sensor 1 >> Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0134: HO2S Circuit Insufficient Activity Sensor 1: Troubleshooting

TROUBLESHOOTING CHART

Step Action Value(s) Yes No
1 Perform an On-Board Diagnostic (OBD II) System Check.
Was the check performed?		 - Go to Step 2 Go to On-Board Diagnostic (OBD II) System Check
2
  1. Install the scan tool to the Data Link Connector (DLC).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the engine above the specified RPM for 2 minutes.

Does the scan tool indicate Closed Loop?		 80 °C (176 °F) 1,200 rpm Go to Step 3 Go to Step 4
3
  1. Review the Freeze Frame data and note the parameters.
  2. Operate the vehicle within the Freeze Frame conditions and Conditions For Setting the DTC as noted.

Does the scan tool indicate Closed Loop?		 - Go to Step 12 Go to Step 4
4
  1. Turn the ignition OFF.
  2. Disconnect HO2S1 connector.
  3. Jumper the terminal 4 of HO2S1 connector and ground.
  4. Turn the ignition ON.

Does the scan tool indicate the HO2S1 voltage within the specified value?		 400 - 500 mV Go to Step 5 Go to Step 8
5 Check the HO2S1 harness connector for malfunction or poor connection and repair as needed.
Is the voltage above the specified value?		 - Go to Step 12 Go to Step 6
6
  1. Idle the engine.
  2. Remove the jumper wire.
  3. Using a voltmeter, measure the voltage between terminal 2 of HO2S1 and ground.

Is the voltage above the specified value?		 600 mV Go to Step 7 Go to Step 11
7
  1. Turn the engine OFF.
  2. Using a voltmeter, measure the voltage between terminal 2 of the HO2S1 and ground.

Is the voltage below the specified value?		 300 mV Go to Step 9 Go to Step 11
8 Check the HO2S1 low circuit for an open or short to ground between terminal 4 of the HO2S1 and terminal E26 of the ECM and repair as needed.
Is the repair complete?		 - Go to Step 12 Go to Step 10
9 Check the HO2S1 signal circuit for an open or short to ground between terminal 2 of the HO2S1 and terminal E34 of the ECM and repair as needed.
Is the repair complete?		 - Go to Step 12 Go to Step 10
10
  1. Turn the ignition OFF.
  2. Replace the ECM.

Is the repair complete?		 - Go to Step 12 -
11 Replace the HO2S1.
Is the repair complete?		 - Go to Step 12 -
12
  1. Using the scan tool, clear the Diagnostic Trouble Codes (DTCs).
  2. Start the engine and idle at normal operating temperature.
  3. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has run and passed?		 - Go to Step 13 Go to Step 2
13 Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?		 - Go to applicable DTC table System OK
scientia non olet · About LEMON Manuals