Engine Oil Pressure Indicator Malfunction
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Engine Oil Pressure Indicator Malfunction
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Diagnostic Fault Information
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Circuit
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Short to Ground
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Open/High Resistance
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Short to Voltage
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Signal Performance
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Signal
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1
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P0520
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1
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-
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Ground
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-
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P0520
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-
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-
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1. Engine Oil Pressure Indicator Malfunction
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Circuit/System Description
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The engine oil pressure switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the engine control module (ECM) should detect a low signal voltage input. With the engine running, the engine oil pressure switch opens and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a message via High Speed CAN-Bus to the body control module (BCM). The BCM then sends a message via Low Speed CAN-Bus to the instrument cluster requesting the engine oil pressure indicator turned ON.
Schematic Reference
Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Indicator/Warning Message Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
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With LLU
With ignition ON, check the diagnostic tool's parameter for ECM - Oil pressure switch. With ignition ON and engine off, the parameter should be Low, and with the engine on it should be OK.
Except LLU
1.
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Ignition ON, command the All Indicators test ON and OFF with the scan tool, verify that the engine oil pressure indicator changes between turn ON and OFF.
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2.
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If the engine oil pressure indicator always stays on or always off, replace the P16 Instrument Cluster.
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3.
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If the engine oil pressure indicator changes between ON and OFF, replace the K20 Engine Control Module.
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With LLU
1.
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Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
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2.
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Ignition ON, verify the scan tool ECM - Engine Oil Pressure Switch parameter is OK.
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3.
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If not the specified value, test for the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
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4.
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Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool ECM - Engine Oil Pressure Switch is Low.
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5.
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If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
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6.
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Command the All Indicators test ON and OFF with the scan tool. The engine oil pressure indicator should turn ON and OFF when changing between the commanded states.
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7.
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If the engine oil pressure indicator always stays on or always off, replace the P16 Instrument Cluster.
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8.
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If all circuits test normal, test or replace the B37 Engine Oil Pressure Switch.
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Static Test
1.
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Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
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2.
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Test for infinite resistance between the signal terminal listed below and ground with the switch in the open position.
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3.
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If not the specified value, replace the B37 Engine Oil Pressure Switch.
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4.
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Test for less than 5 Ω between the signal terminal listed below and ground with the switch in the closed position.
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5.
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If greater than the specified range, replace the B37 Engine Oil Pressure Switch.
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Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.