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HOMESERVICE MANUALSHYUNDAI2005SANTA FE GLS, 2.7 D, AWDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROL SYSTEM DIAGNOSIS (2.7L) (1 OF 2)DTC TROUBLESHOOTING PROCEDURESDTC P0051: HO2S HEATER CIRCUIT LOW (BANK 2/SENSOR 1)CONTROL CIRCUIT INSPECTION

2005 Hyundai Santa Fe GLS, 2.7 D, AWD

Control Circuit Inspection

2005 Hyundai Santa Fe GLS, 2.7 D, AWDSECTION Control Circuit Inspection

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect ECM and HO2S connectors.
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 13 of the ECM harness connector.
  Specification: Approx. 0Ω
  
  Fig 1: Measuring Resistance Between Terminals 4 Of HO2S Heater Harness Connector And 13 Of ECM Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
4. Is resistance within the specification?
  YES
  - Go to next step.
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to ground in control circuit.
1. Measure resistance between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: infinite
  
  Fig 2: Measuring Resistance Between Terminal 4 Of HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
2. Is resistance within the specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure
  NO
  - Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect HO2S and ECM connectors.
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 13 of the ECM harness connector.
  Specification: Approx. 0Ω
  
  Fig 1: Measuring Resistance Between Terminals 4 Of HO2S Heater Harness Connector And 13 Of ECM Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
4. Is resistance within the specification?
  YES
  - Go to next step.
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to power in control circuit
1. Reconnect the ECM connector.
2. Ignition "ON" & Engine "OFF".
3. Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: Approx. 0V
  
  Fig 2: Measuring Voltage Between Terminal 4 Of HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
4. Is voltage within the specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect ECM connector.
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 19 of the ECM harness connector.
  Specification: Approx. 0Ω
  
  Fig 1: Measuring Resistance Between Terminals 4 Of HO2S Heater Harness Connector And 19 Of ECM Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
4. Is resistance within the specification?
  YES
  - Go to next step.
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to ground in control circuit.
1. Measure resistance between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: infinite
  
  Fig 2: Measuring Resistance Between Terminal 4 Of HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
2. Is resistance within the specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect HO2S and ECM connectors.
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 19 of the ECM harness connector.
  Specification: Approx. OΩ
  
  Fig 1: Measuring Resistance Between Terminals 4 Of HO2S Heater Harness Connector And 19 Of ECM Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
4. Is resistance within the specification?
  YES
  - Go to next step.
  NO
  - Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to power in control circuit
1. Reconnect the ECM connector.
2. Ignition "ON" & Engine "OFF".
3. Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: Approx. 0V
  
  Fig 2: Measuring Voltage Between Terminal 4 Of HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
4. Is voltage within the specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.