Accessory Signal: Description and Operation

Low Oil Level Sensor:

DESCRIPTION
The Powertrain Control Module (PCM) controlled warning lamp is intended to alert the driver to an operating condition which may require immediate attention.

OPERATION
The "Low Oil Level" lamp operates as follows:

^ When energized during key "ON," the PCM controlled low oil warning lamp is turned "ON." This indicates the system is functioning properly (one second bulb check).

^ As long as engine coolant temperature is greater than 75°C on shutdown, and at least three minutes have elapsed since the last shutdown, the PCM checks oil level signal upon start-up, to determine either of two conditions:

- Engine oil level is OK (lamp goes OFF").

OR

- Engine oil level is low (lamp stays ON").

^ If three minutes does not elapse since the last ignition "OFF' cycle, and the ignition is turned "ON," the bulb check will turn the "Low Oil Level" lamp "ON" for one second, the PCM will skip reading the oil level sensor and the PCM will turn "OFF' the low oil level indicator as the PCM prepares for the next powerdown activation of the low oil level logic. The logic is designed this way because three minutes is required for the oil to drain back into the pan.

^ If engine coolant temperature is less than 75°C on shutdown, the PCM records the coolant temperature at shutdown. Now, when the engine is restarted, the PCM checks for coolant temperature again. If the coolant temperature has dropped by at least 11 °C since the last shutdown, the PCM checks the oil level signal and determines whether or not the oil level is within the acceptable range.

^ If coolant temperature did not decrease by the required 11 °C, the same action is taken by the PCM as described above, that is, the PCM will skip reading the oil level sensor and turn the lamp "OFF."

^ If Diagnostic Trouble Code (DTC) 14 or 15 or a combination of DTC 36 and 82, occurred anytime during ignition cycle before shutdown, there will be no bulb check upon start-up. In this case, the PCM will not run the test to check oil level.