Did you perform the Instrument Cluster Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

Verify the fault is present.

Does the system operate normally?

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Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Is the oil pressure gage pegged past 80 psi?

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Go to Step 6

Go to Step 4

Does the oil pressure gage stay at 0 psi?

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Go to Step 8

Go to Step 5

1. Ensure that the engine oil level is correct.
2. Ensure that the engine develops adequate oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical - 4.3L engines.
3. Disconnect the oil pressure switch connector.
4. Connect a variable 100 ohm resistance between the oil pressure switch connector terminal A and a good ground.
5. Turn ON the ignition, with the engine OFF.
6. Turn the variable resistance (potentiometer) back and forth from maximum to minimum resistance.

Does the oil pressure gage operate normally?

0 ohms = no oil pressure

88 ohms = maximum oil pressure

Go to Step 12

Go to Step 13

1. Ensure that the engine oil level is correct.
2. Ensure that the engine develops normal oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical - 4.3L engines.
3. Disconnect the oil pressure switch connector.
4. Turn ON the ignition, with the engine OFF.
5. With a DMM measure the voltage between the oil pressure sensor signal circuit and a good ground.

Does the voltage measure within the specified range?

7-9.5 V

Go to Step 12

Go to Step 7

1. Backprobe (in order to prevent damage to the terminal) the cluster connector with a J 39200 DMM.
2. Measure the voltage between the oil pressure sensor signal circuit and a good ground.

Does the voltage measure within the specified range?

7-9.5 volts

Go to Step 11

Go to Step 13

1. Ensure that the engine oil level is correct.
2. Ensure that the engine develops adequate oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical - 4.3L engines.
3. Turn ON the ignition, with the engine OFF.
4. Disconnect the oil pressure sensor connector.

Is the oil pressure gage pegged past 80 psi?

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Go to Step 12

Go to Step 9

1. Disconnect the cluster connector.
2. Remove the connector comb.
3. Connect a test lamp between a good power source and the oil pressure sensor signal circuit.

Does the test lamp illuminate?

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Go to Step 10

Go to Step 13

Repair the short to ground in the oil pressure sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 14

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Repair the open in the oil pressure sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 14

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Replace the oil pressure switch. Refer to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical for 4.3L engines.

Did you complete the replacement?

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Go to Step 14

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Replace the instrument panel cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

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Go to Step 14

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3