LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2011 >> Grand Vitara Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis >> Diagnostic Information and Procedures >> DTC P0037: HO2S Heater Control Circuit Low (Bank-1 Sensor-2); DTC P0038: HO2S Heater Control Circuit High (Bank-1 Sensor-2) >> DTC Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC Troubleshooting

P0037, P0038 DIAGNOSIS PROCEDURE

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:J24B .
2  HO2S heater power supply circuit check 
  1. Turn OFF ignition switch and disconnect connector from HO2S.
  2. Check for proper terminal connection to HO2S.
  3. If connections are OK, turn ignition switch to ON position.
  4. Check that voltage between HO2S heater power supply circuit (A1) and vehicle body ground is battery voltage.

Is it in good condition? 		 Go to Step 3. Repair or replace defective parts or wire harness.
3  HO2S heater drive circuit check 
  1. Turn OFF ignition switch and disconnect connectors from ECM.
  2. Check for proper terminal connection to ECM connectors.
  3. Check that HO2S heater drive circuit (A2) is as follows.
    • Wiring harness resistance of HO2S heater drive circuit is less than 3 Ω.
    • Insulation resistance between HO2S heater drive circuit and vehicle body ground is infinity.
    • Insulation resistance of wire harness is infinity between HO2S heater drive circuit terminal and each terminal at HO2S connector.
    • Circuit voltage of HO2S heater drive circuit is 0 - 1 V with ignition switch in ON position.

Is it in good condition? 		 Go to Step 4. Repair or replace defective wire harness.
4  HO2S check 
  1. Check HO2S heater. See HO2S (HEATED OXYGEN SENSOR) ON-VEHICLE INSPECTION

Is it in good condition? 		 Substitute a known-good ECM and recheck. Replace HO2S.
scientia non olet · About LEMON Manuals