GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Impala 🢒 Engine 🢒 Engine Controls - 3.4L 🢒 DTC P1189

Circuit Description

The engine oil pressure switch closes (signal circuit is low) with low oil pressure and opens (signal circuit is high) with oil pressure above 4.5 psi. The PCM monitors the oil pressure switch signal circuit and sends a class 2 message to the IPC indicating the switch status.

Conditions for Running the DTC
    • DTCs P0117, P0118, and P1114 not set.
    • The ignition is ON with the engine OFF.
    • Engine temperature is 10°C (50°F) less than the last key off temperature.

Conditions for Setting the DTC
    • The PCM detects that the oil pressure switch signal circuit is high with the ignition ON and the engine OFF.
    • The above condition is present for greater than 10 seconds.

Action Taken When the DTC Sets

The PCM stores the conditions that are present when the DTC sets as Failure Records data only. This information is not stored as Freeze Frame data.

Conditions for Clearing the DTC
    • The DTC becomes history when then conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives the clear code command from the scan tool.

Test Description

The number below refer to steps in the diagnostic table.

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

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2
  1. Connect a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Engine Oil Pressure Switch parameter in the PCM Engine Data 2 list.

Does the Engine Oil Pressure Switch parameter display Low?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the oil pressure switch connector.
  3. Connect a 3 amp fused jumper wire between the signal circuit of the oil pressure switch connector and a good ground.
  4. Turn ON the ignition.
  5. With a scan tool, observe the Engine Oil Pressure Switch parameter in the PCM Engine Data 2 list.

Does the Engine Oil Pressure Switch parameter display Low?

Go to Step 6

Go to Step 4

4

Test the signal ciruit of the engine oil pressure switch for an open, high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 5

5

Test the ground circuit of the engine oil pressure switch for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector of the oil pressure switch. 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 10

Go to Step 8

7

Inspect for poor 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 10

Go to Step 9

8

Replace the oil pressure switch. Refer to Engine Oil Pressure Sensor or Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement (3.4L) or Powertrain Control Module Replacement (3.8L) in Engine Controls.

Did you complete the replacement?

Go to Step 10

--

10
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK