P0132

Code P0132, Heated Oxygen Sensor (HO2S) Sensor Circuit (High Signal Voltage):

Heated Oxygen Sensor (HO2S) Circuit:

CIRCUIT DESCRIPTION
The PCM supplies a voltage of about 0.45 volt (450 mV) between terminals "BF9" and "BF10". (If measured with a 10 megohm digital voltmeter, this may read as low as 0.32 volt.) The Heated Oxygen Sensor (HO2S) varies the voltage within a range of about 1 volt (1000 mV) if the exhaust is rich, down to about 0.10 volt (100 mV) if exhaust is lean.

The sensor is like an open circuit and produces no voltage when it is below about 360°C (600°F). DTC P0131, P0132 or an open sensor circuit or cold sensor causes "Open Loop" operation.

DTC PO132 WILL SET WHEN:
^ The HO2S signal voltage on CKT 412 remains above 900 mV for 2 minutes while in "Closed Loop."
^ Throttle angle between 2% and 40%.

ACTION TAKEN (PCM will default to):
A current DTC P0132 will cause the system to operate in "Open Loop" With DTC P0132 set, the MIL (Service Engine Soon) will be illuminated.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Determines if conditions necessary to set DTC P0132 exist.


DIAGNOSTIC AIDS
^ Fuel pressure - System will go rich if pressure is too high. The PCM can compensate for some increase. However, if it gets too high, DTC P0132 may be set. Refer to "Fuel System Diagnosis," CHART A-7. Chart A-7 Fuel System Pressure Test

^ Rich injector - Perform injector balance test. Refer to "CHART C-2A". Chart C-2A Injector Coil Balance Test Procedure

^ Leaking injector - Refer to "CHART A-7". Chart A-7 Fuel System Pressure Test

^ Check for fuel contaminated oil.

^ EVAP canister purge - Check for fuel saturation. If full of fuel, check canister control and hoses. Refer to "Canister Purge," "Evaporative Emission Control (EVAP) System".

^ MAF sensor - An output that causes the PCM to sense a higher than normal air flow can cause the system to go rich. Disconnecting the MAF sensor will allow the PCM to set a fixed value for the sensor. Substitute a different MAF sensor if the rich condition is gone while the sensor is disconnected.

^ Check for leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for fuel.

^ TP sensor - An intermittent TP sensor output will cause the system to go rich due to a false indication of the throttle moving.

^ False rich indication due to silicon contamination of the heated oxygen sensor. This will be indicated by DTC P0132 accompanied by lean driveability conditions and a powdery white deposit on the sensor.

^ Oxygen Sensor - If the HO2S is internally shorted the signal voltage displayed on a Tech 1 will be over 1 volt. Try disconnecting the HO2S with the key "ON," engine "OFF;" if the displayed voltage goes from over 1000 mV to around 450 mV, replace the HO2S.