GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0130: HO2S Circuit Sensor 1

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Heater Control

P0031

P0030, P0135

P0032

--

Heater Supply Voltage

P0013, P0023, P0031, P0458, P2088, P2092

P0030, P0135

--

--

High Signal

P0131

P0135, P2243, P2251

P0132

P0130

Low Signal

P0131

P0131, P0135, P2251

P0132

P0130

Pump Current

P0131

P2243, P2251, P2626

P0132

--

Input Pump Current

P0131

P2237

P0132

--

Circuit/System Description

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust system and provides more information than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine control module (ECM) supplies a voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell in order to maintain a constant voltage in the oxygen sensing cell. The ECM monitors the voltage variation in the sensing cell and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or oxygen ion flow, to the pumping cell. By measuring the amount of current required to maintain the voltage in the sensing cell, the ECM can determine the concentration of oxygen in the exhaust. The HO2S voltage is displayed as a lambda value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1. When the fuel system is lean, the oxygen level will be high and the lambda signal will be high or greater than 1. When the fuel system is rich, the oxygen level will be low, and the lambda signal will be low or less than 1. The ECM uses this information to maintain the correct air/fuel ratio.

Conditions for Running the DTC

    • The engine is operating.
    •  The ignition voltage is between 11-18 volts.
    • DTC P0130 runs continuously once the above conditions are met.

Conditions for Setting the DTC

    • The ECM detects that the HO2S signal voltage is out of range.
    • The above condition exists for less than 4 seconds.

Action Taken When the DTC Sets

DTC P0130 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0130 is a Type B DTC.

Diagnostic Aids

The following table illustrates the ECM connector locations:

ECM Connector Location

X2

X1

Front of Vehicle

    • The front wide band sensor does not toggle or switch like a switching HO2S. The front HO2S signal will be relatively stable for an idling engine.
    • The following table illustrates the typical voltages for the HO2S circuits:

HO2S Circuit

Voltage

    • Ignition ON, Engine OFF
    • HO2S Disconnected

Heater Control

4.6-5.0 V

Heater Supply Voltage

B+

High Signal

2.6-3.1 V

Low Signal

2.2-2.7 V

Pump Current

Less than 0.5 V

Input Pump Current

Less than 0.5 V

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Engine idling at operating temperature. Observe the scan tool Loop Status Bn 1 Sen 1. Verify the scan tool displays Closed Loop.
  2. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the HO2S 1.
  2. Ignition ON, test for 2.5-3.5 volts between the high signal circuit terminal 1 and ground.
  3. If less than the specified range, test the high signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Test for 2-3 volts between the low signal circuit terminal 5 and ground
  5. If less than the specified range, test the low signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the low signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

    Important: The input pumping current circuit and the pump current circuit are connected internally within the ECM. If there is a condition with one of the circuits, the other circuit will be affected.

  6. Test for 50-90 mV between the input pump current circuit terminal 6 and ground.
  7. If less than the specified range, test the input pump circuit and pump current circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the input pump circuit and pump current circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. If all circuits test normal, replace the HO2S 1.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Heated Oxygen Sensor 1 Replacement
    •  Control Module References for engine control module replacement, setup, and programming