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. |
| • | DTC P1635 is not present. |
Conditions for Setting the DTC
| • | The PCM detects that the EOP sensor signal circuit is less than 0.4 volts. |
| • | The above condition is present for greater than 9 seconds. |
Action Taken When the DTC Sets
| • | The PCM records the operating conditions at the time the diagnostic test 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 help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views , Powertrain Control Module Connector End Views , or Powertrain Control Module Connector End Views | ||||
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 - 4.2L | 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 for a high resistance. Refer to Circuit Testing and to 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, for a short to ground, or for a high resistance. Refer to Circuit Testing and to 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 to 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 to 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 and/or Switch Replacement in Engine Mechanical - 4.2L or to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical - 4.8L, 5.3L, or 6.0L. Did you complete the replacement? | -- | Go to Step 12 | -- |
11 |
Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.2L or to Powertrain Control Module Replacement in Engine Controls - 4.8L, 5.3L, or 6.0L.Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
