GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Low Engine Oil Level Indicator Diagnosis

Object Number: 374481 Size: SF
Handling ESD Sensitive Parts Notice
Engine Controls Components
Cell 20: G102, G104, Generator
OBD II Symbol Description Notice

Circuit Description

The Oil Level switch is a normally open switch. When the oil level is within an acceptable range the Oil Level switch closes. The switch opens when the engine oil level drops below a predetermined amount. The VCM turns ON the Oil Level Indicator when the engine oil level drops below a predetermined value.

Diagnostic Aids

The LOW OIL LEVEL message will only appear in the Message Center within a few seconds after the vehicle has been started. The ignition key must be removed from the ignition for 10 seconds, and then start the vehicle to check if the message has been cleared.

An intermittent may be caused by any of the following conditions:

    • A poor connection
    • Rubbed through wire insulation
    • A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This steps checks the Oil Level sensor signal circuit between the VCM and the sensor.

    2.

  2. This steps checks the Oil Level sensor ground circuit between the VCM and the sensor.

    3.

  3. This steps checks for an open in the Oil Level sensor signal circuit between the VCM and the Oil Level sensor.

    4.

  4. This steps checks the Oil Level signal circuit for a short to ground.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Physically check engine oil level.

Did you find a problem?

--

Go to Step 10

Go to Step 3

3

  1. Disconnect the Engine Oil Level Switch harness connector.
  2. Jumper the harness connector terminals (harness side).
  3. Turn ON the ignition leaving the engine OFF.

Does the Message Center display the LOW OIL LEVEL message?

--

Go to Step 8

Go to Step 4

4

  1. Remove the harness connector jumper.
  2. Measure the voltage across the harness connector terminals (harness side) with a J 39200 DMM.

Is the voltage above the specified value?

11 V

Go to Step 8

Go to Step 5

5

Probe the switch ground with a test lamp connected to B+.

Did the test lamp turn ON?

--

Go to Step 6

Go to Step 11

6
  1. Disconnect the VCM C3 connector.
  2. Probe the switch output circuit (switch Harness side) with a test lamp connected to B+.

Did the test lamp turn ON?

--

Go to Step 12

Go to Step 7

7
  1. Jumper the switch output circuit (VCM harness side) to ground.
  2. Probe the switch output circuit (switch harness side) with a test lamp connected to B+.

Did the test lamp turn ON?

--

Go to Step 8

Go to Step 11

8

Check for an improper harness connector connection at the VCM and Oil Level Sensor. Refer to Diagnostic Aids.

Did you find a problem?

--

Go to Step 15

Go to Step 9

9

Check for an improperly operating Message Center display. Refer to Instrument Cluster System Check in Instrument Panel, Gauges, and Console.

Did you find a problem?

--

Go to Step 15

Go to Step 11

10

Fill the engine to the proper oil level. Refer to Engine Oil and Oil Filter Replacement in Engine Mechanical.

Is the action complete?

--

Go to Step 15

--

11
  1. Check for an open in the circuit.
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 15

--

12
  1. Check for a short to ground in the circuit.
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 15

--

13

Replace the Engine Oil Level Switch. Refer to Engine Oil Level Indicator Switch Replacement .

Is the action complete?

--

Go to Step 15

--

14
  1. Replace the VCM.
  2. Program the new VCM. Refer to VCM Replacement/Programming .
  3. Perform the Scan Tool Learn procedure within the Passlock Reprogramming procedure. Refer to PASSLOCK Reprogramming Auto Learn in Theft Deterrent.
  4. Perform the CKP System Variation Learning Procedure. Refer to Crankshaft Position System Variation Learn .

Is the action complete?

--

Go to Step 15

--

15

Operate the vehicle under the conditions that the original problem was encountered.

Is the problem still present?

--

Go to Step 2

System OK