For 1990-2009 cars

### Circuit Description

The powertrain control module (PCM) supplies a voltage of about 0.45 volt between the oxygen sensor (O2S 1) high signal and the low signal circuit. The oxygen sensor (O2S 1) varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 0.10 volt if the exhaust is lean.

The sensor is like an open circuit and produces no voltage when below 315°C (600°F). An open sensor signal circuit or a cold sensor causes an Open Loop operation.

### Conditions For Running The DTC

• | DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0171, P0201, P0202, P0203, P0204, P0300, P0301, P0302, P0303, P0304, P0335, P0440, P0442, P0446, P0506, P0507, P0601, P0602, or P1441 are not set.

• | The engine coolant temperature (ECT) is more than 70°C (158°F).

• | The battery voltage is greater than 10 volts.

• | The fuel level is greater than 10 percent.

• | The engine run time is greater than 10 seconds.

• | Engine is operating in Closed Loop.

• | Throttle position (TP) angle is between 8-50 percent.

• | The manifold absolute pressure (MAP) sensor is greater than 25 kPa.

• | Engine has met the above conditions for 4 seconds.

### Conditions For Setting The DTC

O2S 1 voltage is more than 946 mV for 50 seconds.

Or

O2S 1 voltage is more than 1042 mV for 50 seconds while in deceleration mode.

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | Clear the MIL and the DTC with a scan tool.

### Diagnostic Aids

The DTC P0132 or rich exhaust is most likely caused by one of the following items:

• | Fuel pressure--The system will go rich if fuel pressure is too high. The PCM can compensate for some increase, however, if it gets too high, a DTC P0172 will be set. Refer to DTC P0172 .

• | Leaking injector--A leaking or malfunctioning injector can cause the system to go rich causing a DTC P0132. Refer to Fuel Injector Balance Test with Special Tool or Fuel Injector Balance Test with Tech 2 .

• | Electronic ignition (EI) shielding--An open ICM reference low circuit may result in an EMI or induced electrical noise. The PCM looks at this noise as a crankshaft position (CKP) sensor pulses. The additional pulses result in a higher than actual engine speed signal. The PCM then delivers too much fuel causing the system to go rich. The engine tachometer will also show higher than actual engine speed which can help in diagnosing this problem.

• | The MAP sensor--An output that causes the PCM to sense a higher than normal manifold pressure, or a low vacuum, can cause the system to go rich. Disconnecting the MAP sensor electrical connector will allow the PCM to set a fixed value for the MAP sensor. Substitute a different MAP sensor if the rich condition is gone while the MAP sensor is disconnected.

• | The pressure regulator--Check for a leaking fuel pressure regulator diaphragm by checking for the presence of liquid fuel in the vacuum line to the fuel pressure regulator.

• | The TP sensor--An intermittent TP sensor output will cause the system to go rich due to a false indication of the engine accelerating.

• | O2S 1 contamination--Inspect the O2S 1 sensor for silicone contamination from fuel or the use of improper RTV sealant. The O2S 1 sensor may have a white powdery coating and this will result in a high but false voltage signal, indicating a rich exhaust. The PCM will then reduce the amount of fuel delivered to the engine causing a severe surge or driveability problem.

### Test Description

The number below refers to step number on the diagnostic table:

1. This step determines if DTC P0132 is the result of a hard malfunction or an intermittent condition. You may need to operate the vehicle within the Freeze Frame conditions and the Conditions for Setting the DTC in order to duplicate the malfunction detected by the PCM.

#### DTC P0132 HO2S Circuit High Voltage Sensor 1

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls
2 |

1. Operate the vehicle within the Conditions for Running this DTC.
2. Use a scan tool in order to monitor the O2S voltage for the sensor that applies to this DTC.

Does the O2S voltage measure more than the value specified?

976 mV

Go to Step 4

Go to Step 3

3 | This DTC is intermittent. Are any additional DTCs stored? | -- | Go to Diagnostic Trouble Code (DTC) List | Go to Diagnostic Aids
4 |

1. Turn OFF the ignition.
2. Disconnect the O2S sensor.
3. Jumper the O2S low signal circuit to a good ground.
4. Turn ON the ignition, with the engine OFF.
5. Measure the voltage on the O2S high signal circuit on the PCM side, using a DMM that is connected to a good ground.

Does the voltage measure within the specified value?

351-551 mV

Go to Step 5

Go to Step 6

5 | The O2S is detecting a rich exhaust condition or may be contaminated. Check for one of the following conditions:

• | O2S connector water intrusion

• | Silicon-contaminated O2S

• | Fuel-contaminated engine oil

• | Incorrect fuel pressure. Refer to Fuel System Diagnosis .

• | A leaking fuel pressure regulator

• | Rich fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .

Repair any of the above or similar engine conditions as necessary.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

6 | Test the O2S high signal circuit for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9
7 | Inspect for poor connections at the harness connector of the O2S sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Heated Oxygen Sensor Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8
8 | Important: Before replacing a contaminated O2S, determine and repair the cause of the contamination. Replace the O2S. Refer to Oxygen Sensor Replacement . Did you complete the replacement? | -- | Go to Step 10 | --
9 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | --
10 |

1. Use a scan tool in order to clear the DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 11

Go to Step 2

11 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK