P1189

CIRCUIT DESCRIPTION

Schematic:

The engine oil pressure switch is a normally closed switch that opens with the proper oil pressure. The PCM applies ignition voltage to the oil pressure signal circuit through a pull-up resistor. 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 checks 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
^ No ECT, or Starter Request DTCs are set.
^ The starter request (ignition switch in the crank position) has not been activated for this key ON ignition cycle.
^ The engine coolant temperature at the last key OFF was above 80°C (176°F).
^ The engine coolant temperature at the current key ON is 10°C (18°F) cooler that the engine coolant temperature at the last key OFF.

OR

The amount of time between the last key OFF and the current key ON is more than 4 minutes.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects a high voltage input on the engine oil pressure signal circuit.
^ The condition exists for at least 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM will store the conditions 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 DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermiffent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions

TEST DESCRIPTION

Steps 1 - 8:

The numbers below refer to the step numbers on the diagnostic table.
8. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read only memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.