DTC P0037 / P0038: HO2S Heater Control Circuit Low / High (Sensor-2) - Suzuki Jimny Workshop Manual
1A
DTC P0037 / P0038: HO2S Heater Control Circuit Low / High (Sensor-2)
Wiring Diagram
| 1. | Shield wire | 4. | “IG” fuse | 7. | To HO2S-1 heater | 10. | Relay box |
| 2. | Ignition switch | 5. | HO2S-2 | 8. | ECM | 11. | “IGN1” fuse |
| 3. | Circuit fuse box | 6. | Heater | 9. | To other sensor |
DTC Detecting Condition and Trouble Area
| DTC detecting condition | Trouble area |
|---|---|
|
Current of HO2S-2 heater is more than specified value or less than specified value for 5 seconds continuously.
(2 driving cycle detection logic) |
•
HO2S-2 heater circuit
• HO2S-2 heater • ECM |
DTC Confirmation Procedure
1)
With ignition switch turned OFF, connect scan tool.
2)
Turn ON ignition switch and clear DTC using scan tool.
3)
Start engine and warm up to normal operating temperature.
4)
Run engine at idle speed for 1 min.
5)
Check DTC and pending DTC.
DTC Troubleshooting
| Step | Action | YES | NO |
|---|---|---|---|
| 1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
|
|
| 2 |
HO2S-2 heater power circuit check
1)
Disconnect connector from HO2S-2 sensor with ignition switch turned OFF.
2)
Check for proper connection to HO2S-2 sensor at “BLK/WHT” and “RED/BLU” wire terminals.
3)
If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal of HO2S-2 sensor connector and engine ground with ignition switch turned ON.
Is voltage over 10 V?
|
Go to Step 3.
|
“BLK/WHT” wire open circuit or shorted to ground circuit.
|
| 3 |
HO2S-2 heater power circuit check
1)
Disconnect connectors from ECM with ignition switch turned OFF.
2)
Measure resistance between “BLK/WHT” wire terminal of HO2S-2 sensor connector and “E118-28” terminal wire of ECM connector.
Is resistance below 5 Ω?
|
Go to Step 4.
|
“BLK/WHT” wire high resistance circuit.
|
| 4 |
HO2S-2 heater drive circuit check
1)
Measure resistance between “RED/BLU” wire terminal of HO2S-2 sensor connector and vehicle body ground.
Is resistance infinity?
|
Go to Step 5.
|
“RED/BLU” wire shorted to ground circuit.
|
| 5 |
HO2S-2 heater drive circuit check
1)
Turn ON ignition switch.
2)
Measure voltage between “RED/BLU” wire terminal of HO2S-2 sensor connector and vehicle body ground.
Is voltage 0 V?
|
Go to Step 6.
|
“RED/BLU” wire shorted to power circuit.
|
| 6 |
HO2S-2 heater drive circuit check
1)
Connect connector to HO2S-2 with ignition switch turned OFF.
2)
Turn ON ignition switch.
3)
Measure voltage between “E117-3” terminal of disconnected ECM connector and vehicle body ground.
Is voltage over 10 V?
|
Go to Step 7.
|
“RED/BLU” wire open circuit.
|
| 7 |
HO2S-2 heater check
1)
Disconnect HO2S-2 coupler with ignition switch turned OFF.
2)
Check HO2S-2 heater resistance referring to
Heated Oxygen Sensor (HO2S-1 and HO2S-2) Heater On-Vehicle Inspection:M13A
.
Is resistance within specified value?
|
Go to Step 8.
|
Replace HO2S-2.
|
| 8 |
HO2S-2 heater power circuit check
1)
Connect connector to HO2S-2 with ignition switch turned OFF.
2)
Measure resistance between “E118-28” and “E117-3” terminals of ECM connector.
Is resistance below 30 Ω?
|
HO2S-2 heater circuit are OK.
Substitute a known-good ECM and recheck.
|
“RED/BLU” wire high resistance circuit.
|
NOTE:
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.