GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Rendezvous - FWD 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC P1189

Circuit Description

With low oil pressure, the engine oil pressure (EOP) switch closes, and the signal circuit is low. With oil pressure in the normal range, the engine oil pressure switch opens, and the signal circuit is high. The PCM monitors the engine oil pressure switch signal circuit and sends a class 2 message to the IPC indicating the switch status.

Conditions for Running the DTC
    • The ignition is ON, with the engine OFF.
    • DTC P0117 is not set.
    • DTC P0118 is not set.
    • DTC P1111 is not set.
    • DTC P1114 is not set.

Conditions for Setting the DTC
    • The PCM detects that the engine oil pressure switch signal circuit is low.
    • The above condition is present for greater than 10 seconds.

Action Taken When the DTC Sets
    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as Failure Records data only. The information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC
    • A history DTC will clear after 40 consecutive malfunction free warm-up cycles.
    • The PCM receives the clear code command from the scan tool.

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the IPC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Important: Do not turn the key to the crank position or engage the starter at any time during diagnosis.

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

Does the Engine Oil Pressure parameter display OK?

Go to Step 3

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

3

  1. Turn the ignition OFF.
  2. Disconnect the engine oil pressure switch.
  3. Connect a fused jumper between the engine oil pressure switch signal circuit and a good ground.
  4. With a scan tool, observe the Engine Oil Pressure parameter in the PCM IPC data list.

Does the Engine Oil Pressure parameter display Low?

Go to Step 6

Go to Step 4

4

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

Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

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

Did you find and correct the condition?

Go to Step 9

Go to Step 8

6

Inspect for poor connections at the engine oil pressure switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

Replace the engine oil pressure switch. Refer to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical.

Did you complete the replacement?

Go to Step 9

--

8

Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the replacement?

Go to Step 9

--

9
  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