Suzuki XL7 2007 Service Manual page 199

Circuit/System Verification
NOTE
It may take up to 8 minutes for the DTC to set.
1. With the engine at normal operating temperature,
operate the engine above 1,200 RPM for 2 minutes
and then allow the engine to idle. DTCs P0135,
P0141, P0155, or P0161 should not set.
2. If the vehicle passes the Circuit/System Verification
Test, then operate the vehicle within the conditions
for running the DTC. You may also operate the
vehicle within the conditions that are captured in the
Freeze Frame/Failure Records List.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector of
the appropriate HO2S.
2. Ignition ON, test for B+ on the HO2S ignition voltage
circuit terminal C of the HO2S harness connector.
➢ If less than the specified value, repair the ignition
voltage circuit of the HO2S heater for a short to
ground or an open/high resistance.
3. Ignition OFF, connect a test lamp between the heater
control circuit terminal D and B+.
➢ If test lamp illuminates, test the heater control
circuit for a short to ground. If the circuit/
connections test normal, replace the ECM.
4. Idle the engine, and verify the test lamp illuminates
or flashes with bright intensity.
➢ If the test lamp is always OFF, test the control
circuit for an open/high resistance. If the circuit/
connections test normal, replace the ECM.
NOTE
The control circuit for the HO2S heater is
pulled-up to voltage within the ECM, 2.0-3.0
volts on the control circuit is normal.
5. Ignition ON, test for 2.0-3.0 volts between the control
circuit terminal D and ground.
➢ If not within the specified range, test the control
circuit for a short to voltage. If the circuit/
connections test normal, replace the ECM.
6. If all circuits/connections test normal, test or replace
the HO2S.
Engine General Information and Diagnosis:
Component Testing
1. Ignition OFF, disconnect the harness connector of
the appropriate HO2S.
2. Test the HO2S heater resistance for 3-35 ohms.
➢ If the resistance is out of the specified range,
replace the HO2S.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Heated Oxygen Sensor Replacement - Bank 1
Sensor 1: "
• "Heated Oxygen Sensor Replacement - Bank 1
Sensor 2: "
• "Heated Oxygen Sensor Replacement - Bank 2
Sensor 1: "
• "Heated Oxygen Sensor Replacement - Bank 2
Sensor 2: "
• "Control Module References: " for engine control
module replacement, setup, and programming
1A-94