Circuit Description
The Engine Oil Level Switch is a simple float switch that is grounded when the engine oil level is OK. The PCM checks the Engine Oil Level switch circuit at startup. Before checking the state of the Engine Oil Level switch, the PCM performs a test routine based on time and engine coolant temperature to ensure that the engine oil has drained back into the sump. To test for low oil level at startup, one of the following conditions must be present:
| • | If the engine coolant temperature was between 15°C (59°F) and 130°C (266°F) at the last key OFF, the engine coolant temperature at key ON must be at least 12°C (22°F) cooler than the engine coolant temperature at the last key OFF. |
| • | If the engine coolant temperature was higher than 100°C (212°F) at the last key OFF, the time between last key OFF and the present key ON must be sufficient to allow the oil to drain back to the sump. The PCM will remain powered up for 10 seconds to ensure that the oil has drained back to the sump. If the key is turned back ON while the PCM is still powered up, the oil level will not be tested. |
The Low Oil Level Lamp will be illuminated for approximately 7 minutes when the PCM checks for low oil level and the Engine Oil Level switch indicates that a low oil level condition exists (Engine Oil Level switch circuit not grounded). When the ignition is first turned ON, the PCM commands the Low Oil Level lamp ON for a brief period of time to test the bulb.
Diagnostic Aids
For diagnosis of the instrument panel, perform the System Check in the Instrument Cluster section of Electrical Diagnosis.
Check for the following conditions:
| • | Poor connection at PCM or oil level sensor. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM and turn the ignition ON. Observe a voltmeter connected to the affected PCM output circuit while moving connectors and wiring harnesses related to the PCM output circuit. A change in voltage will indicate the location of the fault. |
| • | Engine Oil Level Switch circuit: If the problem with the Low Oil Level lamp can not be isolated using the Engine Oil Level Switch Diagnostic table, use the PCM Controlled Lamps Diagnostic table. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 |
Important: This table assumes that the oil level is at the proper level or the oil level was low and the Low Oil Level message never was displayed. Check for BCM DTCs for the Driver Information Center. Is the voltage at the specified value? | B+ | ||
3 | Measure the voltage at the terminal A to the terminal B of the Oil Level sensor connector using a DMM. Is the voltage at the specified value? | B+ | ||
4 |
Does the DMM indicate continuity? | -- | ||
5 | Probe the Oil Level sensor input circuit using a J 35616-200 Test Lamp that is connected to B+. Does the test lamp illuminate? | |||
6 |
Did you find and correct the condition? | -- | System OK | |
7 | Repair the open ground circuit. Refer to Wiring Repairs . Is the action complete? | -- | System OK | -- |
8 | Repair the open signal circuit. Refer to Wiring Repairs . Is the action complete? | -- | System OK | -- |
9 | Repair the signal circuit for a ground. Refer to Wiring Repairs . Is the action complete? | -- | System OK | -- |
10 |
Did you find and correct the condition? | -- | System OK | |
11 |
Important: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | System OK | -- |
12 | Replace the Oil Level sensor. Is the action complete? | System OK | -- |
