Circuit Description
The powertrain control module (PCM) applies battery voltage through a pull-up resistor to the engine oil pressure switch circuit. The PCM monitors the applied voltage on the engine oil pressure switch circuit. If the ignition is turned ON with the engine OFF, or if the engine oil pressure is less than 35 kPa (5 psi), the engine oil pressure switch grounds the PCM voltage input. The PCM sends the engine oil pressure information via Class 2 serial data to the instrument panel cluster (IPC) . The IPC controls the engine oil pressure indicator.
Diagnostic Aids
The low oil pressure message may not appear if other messages are being commanded, such as the rear compartment lid open, or driver or passenger doors ajar. Before diagnosing a low oil pressure condition ensure that all of the doors and the compartment lids are completely closed. For diagnosis of the IPC, perform the Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges, and Console.
Inspect for the following conditions:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
2 | Are any PCM, IPC, or UXXXX communication DTCs stored? | -- | Go to the applicable DTCs | |||||
3 | Is the engine oil pressure Indicator ON? | -- | ||||||
4 | Test the engine for correct oil level. Is the correct engine oil level indicated? | -- | Go to Oil Consumption Diagnosis in Engine Mechanical | |||||
5 | Test the engine oil pressure with a manual pressure gauge. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical. Is the correct engine oil pressure indicated? | -- | Go to Oil Pressure Diagnosis and Testing in Engine Mechanical | |||||
6 |
Does the test lamp illuminate? | -- | ||||||
7 | Test for the following circuit conditions:
Did you find and correct the condition? | -- | ||||||
8 |
Does the test lamp illuminate? | -- | ||||||
9 | Test the IP Driver Information Display for correct operation. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||
10 | Replace the engine oil pressure switch. Did you complete the replacement? | -- | -- | |||||
11 |
Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the repair? | -- | -- | |||||
12 | Test for the proper operation of oil pressure indicator. Refer to Diagnostic Starting Point in Instrument Panel, Gauges, and Console and Oil Pressure Diagnosis and Testing in Engine Mechanical. Is the correct operation indicated? | -- | -- |
