GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 Engine Oil Pressure Gage Inaccurate or Inoperative
Table 1: Engine Oil Pressure Gauge Test Specification Table

Step

Action

Values

Yes

No

1

Did you perform the Instrument Cluster System Check?

--

Go to Step 2

Go to Instrument Cluster System Check

2

The engine should be at operating temperature before performing this test.

  1. Remove the engine oil pressure gauge switch.
  2. Install the J 36648 Oil Pressure Gauge Adapter and J 21867 Oil Pressure Gauge.
  3. Start the engine and measure the oil pressure at idle speed.

Is the oil pressure at 150 kPa (21.7 psi minimum)?

--

Go to Step 3

Go to Oil Pressure Diagnosis and Testing

3

Does the oil pressure gauge read inaccurately?

--

Go to Step 7

Go to Step 4

4

Is the oil pressure gauge inoperative?

--

Go to Step 5

--

5
  1. Disconnect connector C2 from the engine oil pressure gauge switch.
  2. Turn ON the ignition switch.
  3. Use a DMM in order to measure the voltage at connector C2 terminal 1.

Is the voltage within the specified range?

B+

Go to Step 6

Go to Step 7

6

Measure the resistance from terminal 1 of the engine oil pressure gauge switch to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 9

Go to Step 10

7
  1. Remove the gauge cluster and disconnect the connector.
  2. Measure the resistance of the oil pressure sensor circuit between gauge cluster connector terminal 26 and gauge switch terminal 1.

Is the resistance within the specified range?

0-5 ohms

Go to Step 11

Go to Step 12

8
  1. Refer to the specification table below when you test the cluster.
  2. Use the J 33431-C Signal Generator tool to dial in the resistance. If this tool is not available substitute a resistor or adjustable rheostat.
  3. Cycle the ignition switch after you dial a new resistor value. The gauge cluster might take several minutes or longer to update if you do not cycle the switch.

Do the obtained test results match the values in the table below?

--

Go to Step 9

Go to Step 13

9

Replace the engine oil pressure gauge switch.

Is the replacement complete?

--

Go to Step 15

--

10
  1. Verify that the engine oil pressure gauge switch is installed properly.
  2. Test for possible intermittent operation of the gauge switch.
  3. Remove the gauge switch.
  4. Using the DMM on the ohms scale, connect the leads to terminal 1 and the base of the switch.
  5. While monitoring the DMM move the switch around and look for the resistance to drop below the specified value.

Did you find a problem with the gauge switch?

5 ohms

Go to Step 9

Go to Step 13

11

Measure the resistance from gauge cluster connector terminal 26 or gauge switch connector terminal 1 to ground

Is the resistance within the specified range?

OL

Go to Step 13

Go to Step 14

12

Locate and repair the open circuit in CKTs PB1 or PB90.

Is the repair complete?

--

Go to Step 15

--

13

Replace the gauge cluster.

Is the replacement complete?

--

Go to Step 15

--

14

Locate and repair the short to ground in CKTs PB1 or PB90.

Is the repair complete?

--

Go to Step 15

--

15
  1. Connect all connectors and components that you previously removed.
  2. Test the oil pressure gauge.

Does the oil pressure gauge operate properly?

--

System OK

Go to Step 2

Engine Oil Pressure Gauge Test Specification Table

Ohms ohms (Approximate)

Display Value (psi)

200

80

184

70

168

60

151

50

99

40

48

30

37

20

27

10

16

0