Circuit Description
The engine oil pressure switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the PCM should detect a low signal voltage input. With the engine running, the pressure switch opens, and the PCM should detect a high signal voltage input. The PCM tests the state of the engine oil pressure circuit with the ignition switch turned ON, and the engine turned OFF. If the PCM detects a high voltage input on the engine oil pressure signal circuit, DTC P1189 will set.
Conditions for Running the DTC
| • | The ignition is ON, with the engine OFF. |
| • | DTC codes P0117, P0118, P1111, and P1114 are not set. |
Conditions for Setting the DTC
| • | The PCM detects that the engine oil pressure switch signal circuit is high. |
| • | 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 Fail 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 warm-up cycles have occurred without a malfunction. |
| • | 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 | |
2 |
Important: Do not turn the key to the crank position or engage the starter at any time during diagnosis.
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 |
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 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 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 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 |
Does the DTC reset? | Go to Step 2 | System OK |
