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 switch is turned ON, with the engine not running, or engine oil pressure is below 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
Inspect for the following conditions:
| • | Poor connections -- Inspect PCM and harness connectors for: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connection |
| • | Damaged harness -- Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the engine oil pressure switch, turn ON the ignition and observe a DMM connected between the engine oil pressure switch connector terminals while moving wiring harnesses related to the Engine Oil Pressure Switch circuit. A change in voltage will indicate the location of the fault. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||||||
2 | Are any other DTCs set? | -- | ||||||
3 | Is the engine oil pressure indicator ON? | -- | ||||||
4 | Inspect for correct oil level. Is the correct oil level indicated? | -- | ||||||
5 | Test the engine oil pressure with a manual pressure gauge. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical. Is proper engine oil pressure indicated? | -- | ||||||
6 |
Does the test lamp illuminate? | -- | ||||||
7 |
Does the test lamp illuminate? | -- | ||||||
8 |
Did you find and correct the condition? | -- | ||||||
9 |
Did you find and correct the condition? | -- | ||||||
10 | Locate and repair the following circuit conditions:
Did you find and correct the condition? | -- | -- | |||||
11 | Determine the cause of low oil. Refer to Oil Consumption Diagnosis or Oil Leak Diagnosis in Engine Mechanical. Did you find and correct the condition? | -- | -- | |||||
12 | Determine the cause of low oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical. Did you find and correct the condition? | -- | -- | |||||
13 | Test the Communication circuit for correct operation. Refer to ENGINE OIL PRESSURE Message Always On in Instrument Panel, Gauges, and Console. Did you find and correct the condition? | -- | ||||||
14 | Replace the engine oil pressure switch. Is the action complete? | -- | -- | |||||
15 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |||||
16 | Test for the proper operation of the oil pressure indicator. Is the correct operation indicated? | -- | System OK |
