The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean. The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. The ECM compares the stored HO2S voltage samples taken within each sample period and determines if the majority of the samples are out of the operating range.

The ECM detects that the HO2S signal voltage is out of range for more than 4 seconds.

DTC P2232 is a Type B DTC.

DTC P2232 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. Ignition ON, observe the appropriate scan tool HO2S voltage parameter. The reading should be less than 1,050 mV.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
2. Ignition ON, verify the scan tool HO2S parameter is between 350-500 mV.

⇒	If greater than the specified range, test the signal circuit for a short to the heater circuit. If the circuit tests normal, replace the ECM.

3. If all circuits test normal, replace the applicable HO2S.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.