Captiva

DTC P2A00 - LNP or LNQ

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust stream more quickly and accurately 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 signal 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 signal voltage. The ECM monitors the voltage variation on the signal circuit and attempts to keep the voltage constant by increasing or decreasing the amount of current flow or reversing the direction of the current flow to the pumping cell. By measuring the direction and amount of current required to maintain the signal voltage.

The ECM detects that the HO2S 1 voltage is greater than 1 100 mV for greater than 20 s after closed loop is enabled.

DTC P2A00 00 is a Type B DTC.

DTC P2A00 00 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the DTC information with a scan tool. DTC P0030, P0031, P0032, P2237, P2238, P2245, P2246 or P2251 should not be set.

⇒	If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

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 you observed from the Freeze Frame/Failure Records data.

Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector at the B52 Heated Oxygen Sensor.
2. Disconnect the X1 harness connector at the K20 Engine Control Module.
3. Test for less than 5 Ω between both the harness connectors on the terminals as listed below:

•	B52 Heated Oxygen Sensor Terminal A and the K20 Engine Control Module terminal 55

•	B52 Heated Oxygen Sensor Terminal B and the K20 Engine Control Module terminal 54

•	B52 Heated Oxygen Sensor Terminal E and the K20 Engine Control Module terminal 57

•	B52 Heated Oxygen Sensor Terminal F and the K20 Engine Control Module terminal 56

⇒	If greater than the specified range, test the circuit for an open/high resistance.

4. Test for infinite resistance between each B52 Heated Oxygen Sensor circuit terminal and ground.

⇒	If less than the specified value, repair the short to ground as necessary.

5. Test for infinite resistance between each B52 Heated Oxygen Sensor circuit terminals.

⇒	If less than the specified value, repair as necessary.

6. Ignition ON, test for less than 0.3 V between each B52 Heated Oxygen Sensor circuit terminal and ground.

⇒	If greater than the specified range, repair the short to voltage as necessary.

7. If all circuits test normal, replace the B52 Heated Oxygen Sensor and verify the DTC does not reset.

⇒	If the DTC resets, replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.