Circuit Description
The engine oil pressure (EOP) sensor changes resistance based on engine oil pressure. The PCM monitors the signal circuit of the EOP sensor. When the oil pressure is high, the sensor resistance is high and the PCM senses a high signal voltage. When the oil pressure is low, the sensor resistance is low and the PCM senses a low signal voltage. The PCM sends the engine oil pressure information to the IPC via the class 2 serial data circuit.
Conditions for Running the DTC
| • | The engine is running. |
| • | P1635 is not set. |
Conditions for Setting the DTC
| • | The PCM detects that the EOP sensor signal circuit is less than 0.4 volts. |
| • | The above conditions are present for greater than 9 seconds. |
Action Taken When the DTC Sets
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM displays this information in the Failure Records on the scan tool. |
| • | The instrument panel cluster (IPC) illuminates the engine oil pressure indicator. |
Conditions for Clearing the DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction free warm-up cycles. |
| • | The PCM receives a clear code command from the scan tool. |
Diagnostic Aids
Using the Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail.
Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics | ||||
1 | Did you perform the Instrument Cluster Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the Engine Oil Pressure Sensor parameter display less than the specified value? | 0.4 V | Go to Step 3 | Go to Diagnostic Aids |
3 | Is DTC P1635 current in the PCM? | -- | Go to DTC P1635 in Engine Controls | Go to Step 4 |
Does the Engine Oil Pressure Sensor parameter display greater than the specified value? | 4.6 V | Go to Step 8 | Go to Step 5 | |
5 |
Does the voltage measure greater than the specified value? | 4.6 V | Go to Step 7 | Go to Step 6 |
6 | Test the 5 volt reference circuit of the EOP sensor for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 |
7 | Test the EOP sensor signal circuit for an open, a short to ground, or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the EOP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 |
10 | Replace the EOP sensor. Refer to Engine Oil Pressure Sensor or Switch Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
11 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls. Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
