Suzuki 2006 SX4, Service Manual

Page: 105 / 1478

Engine General Information and Diagnosis: 1A-61
DTC P0037 / P0038: HO2S Heater Control Circuit Low / High (Sensor-2, Bank-1)
S6RW0C1104016
Wiring Diagram
Refer to “DTC P0030: HO2S Heater Control Circuit (Sensor-1, Bank-1)”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle speed for 1 min. or more.
5) Check DTC and pending DTC.
DTC Troubleshooting
DTC detecting condition Trouble area
P0037:
HO2S circuit voltage is lower than specification for specified time even
though control duty ratio of HO2S heater is less than 75% with engine
running. (Heater control duty pulse is not detected in its monitor
signal)
(2 driving cycle detection logic)
P0038:
HO2S circuit voltage is higher than specification for specified time
even though control duty ratio of HO2S heater is more than 25% with
engine running. (Heater control duty pulse is not detected in its
monitor signal)
(2 driving cycle detection logic)
• HO2S heater and/or its circuit
• ECM
Step Action Yes No
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2 HO2S heater and its circuit check
1) Disconnect connector from HO2S with ignition switch
turned OFF.
2) Check for proper terminal connection to HO2S
connector.
3) If connections are OK, check that HO2S heater power
supply circuit is as follows.
• Circuit voltage between “Power supply circuit of HO2S
heater” and vehicle body ground is battery voltage
with ignition switch turned ON.
Is it in good condition?
Go to Step 3. Repair or replace
defective wiring harness
/ connector.
3 HO2S heater circuit check
1) Check that HO2S heater control circuit is as follows.
• Circuit voltage between “Control circuit of HO2S
heater” and vehicle body ground is 0 V with ignition
switch turned ON.
Is it good condition?
Go to Step 4. Repair or replace
defective wiring harness
/ connector.