GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Bonneville 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Engine Oil Pressure Switch Diagnosis

Object Number: 574383 Size: SF
Engine Controls Components
OBD II Symbol Description Notice
Sensors
Handling ESD Sensitive Parts Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice

Circuit Description

The engine oil pressure sensor is a solid state transducer. The engine oil pressure sensor sends oil pressure information to the PCM. The PCM transmits the oil pressure information to the instrument panel cluster (IPC) via the serial data CKT 1807.

The engine oil pressure is displayed on the scan tool in volts. A low voltage reading indicates a low oil pressure. As the oil pressure increases, the voltage level also increases. The normal range of the sensor signal voltage is 0.5 volts at 0 kPa (0 psi) to 4.5 volts at 883 kPa (128 psi).

Diagnostic Aids

For diagnosis of the instrument panel, refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console.

Check for the following conditions:

    • A faulty connection at the PCM or the engine oil pressure sensor, Inspect harness connectors for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals, use a corresponding mating terminal to test for proper terminal tension.
       - Faulty terminal to wire connections
    • Inspect the wiring harness for damage.
    • The engine oil pressure sensor diagnostic table is intended to isolate electrical faults that affect the engine oil pressure sensor, the PCM, and related circuits. If a problem with engine oil pressure can not be isolated using the diagnostic table, refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests for the proper operation of the circuit in the low voltage range.

    2.

  2. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.

    3.

  3. Tests for a short to voltage in the 5 volt reference circuit.

    4.

  4. Tests for a high resistance or an open in the ground circuit.

    5.

  5. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). If the PCM is replaced, the new PCM must be programmed.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Install a scan tool.
  2. Turn on the ignition, leaving the engine off.
  3. With the scan tool, observe the oil pressure sensor data parameter in the Powertrain Control Module data list.

Is the oil pressure within the specified range?

4.5-5.0 V

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn off the ignition.
  2. Disconnect the oil pressure sensor.
  3. Turn on the ignition, with the engine off.
  4. With a scan tool, observe the oil pressure sensor data parameter.

Does the scan tool indicate that the oil pressure sensor data parameter is less than the specified value?

4.5 V

Go to Step 4

Go to Step 10

4

  1. Turn off the ignition.
  2. Connect a 3 amp fused jumper between the 5 volt reference circuit and the signal circuit of the oil pressure sensor.
  3. Turn on the ignition, leaving the engine off.
  4. Use a scan tool in order to observe the oil pressure sensor data.

Is the oil pressure more than the specified value?

5.0 V

Go to Step 5

Go to Step 8

5

  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5 volt reference circuit and the ground circuit of the sensor.

Is the voltage less than the specified value?

4.9 V

Go to Step 6

Go to Step 7

6

  1. Turn off the ignition.

    2. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  2. Disconnect the negative battery cable.
  3. Measure the resistance from the ground circuit of the sensor to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 12

Go to Step 11

7

Test the 5 volt reference circuit of the sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

8

Test the 5 volt reference circuit of the sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 9

9

Test the signal circuit of the sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

10

Test the signal circuit of the sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

11
  1. Disconnect the PCM.
  2. Test the ground circuit of the sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

12

Inspect for faulty connections at the harness connector of the sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

13

Inspect for faulty connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 15

14

Replace the oil pressure sensor.

Did you complete the repair?

--

Go to Step 16

--

15

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Did you complete the repair?

--

Go to Step 16

--

16
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

--

Go to Step 2

System OK