GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Turn the ignition switch to the RUN position.

Does the SERVICE ENGINE SOON indicator illuminate?

--

Go to Step 2

Refer to All Gauges, and Indicators Inop except Turn Signals, High Beam, Seatbelt Indicators and Illumination Lamps

2

  1. Disconnect the engine oil pressure switch connector.
  2. Connect a fused 3 amp jumper between the engine oil pressure switch connector terminal A and ground.
  3. Turn the ignition switch to the RUN position.

Does the oil pressure warning indicator illuminate?

--

Go to Step 3

Go to Step 4

3

  1. Inspect for a poor connection at the engine oil pressure switch connector.
  2. Replace the engine oil pressure switch. Refer to Engine Controls.
  3. Inspect the system.

Is the symptom still present?

--

Go to Step 4

System OK

4

Inspect for a poor connection or an open in CKT 31.

Does a poor connection or an open in CKT 31 exist?

--

Go to Step 5

Go to Step 6

5

  1. Repair the poor connection or the open in CKT 31.
  2. Inspect the system.

Is the symptom still present?

--

Go to Step 6

System OK

6

  1. Inspect the warning indicator bulb and the bulb connection.
  2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .
  3. Inspect the system.

Is the symptom still present?

--

--

System OK