GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The engine oil level switch grounds when the oil level is at the proper level. With the ignition ON, and the engine OFF, the engine control module (ECM) should detect full oil level or a low voltage on the signal circuit of the engine oil level switch. When the engine speed is at least 2000 RPM, the ECM should detect a transition from a low voltage to a high voltage on the signal circuit of the engine oil level switch.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1617 Engine Oil Level Switch Circuit

Conditions for Running the DTC

    • The vehicle is travelling at a speed greater than 5 km/h (3 mph).
    • The throttle position is greater than 5 percent.
    • The engine speed is at least 2000 RPM.
    • The vehicle is cruising and is not accelerating.
    • The following DTCs are not set:
       - P0122
       - P0123
       - P0506
       - P0507

Conditions for Setting the DTC

    • The ECM does not detect a transition from a low voltage to a high voltage, when the engine speed is at least 2000 RPM.
    • The above condition is present for at least 5 minutes.
    • The condition may be present for up to 25 minutes before setting the DTC.

Action Taken When the DTC Sets

The ECM records the operating conditions at the time when the diagnostic test fails. The ECM displays this information in the Failure Records on the scan tool.

Conditions for Clearing the DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC is cleared after 40 malfunction free warm-up cycles.
    • The ECM receives the clear code command from the scan tool.

Diagnostic Aids

The Failure Records may help find 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 the Pass Counter can also aid determining 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.

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the Engine Oil Level Switch parameter in the engine control module (ECM) Engine Data 2 data list.

Does the Engine Oil Level Switch parameter display Low?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the engine oil level switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Engine Oil Level Switch parameter in the ECM Engine Data 2 data list.

Does the Engine Oil Level Switch parameter display Low?

Go to Step 6

Go to Step 4

4

Test the signal circuit of the engine oil level switch for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

Inspect for poor connections at the harness connector of the ECM. 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 9

Go to Step 8

6

Inspect for poor connections at the harness connector of the engine oil level switch. 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 9

Go to Step 7

7

Replace the engine oil level switch. Refer to Engine Oil Level Sensor and/or Switch Replacement in Engine Mechanical.

Did you complete the replacement?

Go to Step 9

--

8

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

--

9

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK