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2009 GMC Sierra 5.3L Eng 1500
OIL PRESSURE GAUGE
REQUESTED INFORMATION
Test Procedure [ Cylinder Deactivation (Active Fuel Management) Oil Pressure Relief
Valve Diagnosis And Testing ]
IMPORTANT:
1. Cylinder Deactivation (Active Fuel
Management) Oil Pressure Relief
Valve Diagnosis and Testing is
applicable for RPO
LH6/LMG/LY5/LC9/L76/LY2/LY6/L9H.
2. This test is performed to verify the
operation of the active fuel
management oil pressure relief valve
located in the oil pan. Refer to
Cylinder Deactivation (Active Fuel
Management) System Description
and Lubrication Description (RPO
LY2) or Lubrication Description (RPO
LH6/LMG/LY5/LC9) or Lubrication
Description (RPO LY6/L9H) or
Lubrication Description (RPO L76) .
1. Remove the oil filter and install the EN-47971 (1). See Special Tools .
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Fig 1: View Of Special Tools: Oil Pressure Gage & Adapter
Courtesy of GENERAL MOTORS CORP.
2. Install the J 21867 (2), or equivalent, to the EN-47971 (1). See Special Tools .
3. Remove the oil pressure sensor and install the J-21867-16 . See Special Tools .
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Fig 2: View Of Oil Pressure Sensor
Courtesy of GENERAL MOTORS CORP.
4. Install the J 21867 (1), or equivalent, to the J-21867-16 (2). See Special Tools .
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Fig 3: Measuring Oil Pressure While Observing Both Gages
Courtesy of GENERAL MOTORS CORP.
5. Run the engine and measure the engine oil pressure while observing both gages.
Operate the throttle, as required, to increase and decrease the engine oil pressure.
1. With the engine running and the lower pressure gage (2) measuring below 379 kPa (55
psi), both gages should display the same pressure reading. If the readings are not the
same and the lower gage (2) has a higher reading, the active fuel management oil
pressure relief valve is stuck in the open position or the valve lifter oil manifold filter is
plugged.
2. With the engine running and the lower pressure gage (2) measuring above 379 kPa (55
psi), the upper gage (1) should display no greater than 379-517 kPa (55-75 psi). If the
reading on the upper gage (1) is greater than 517 kPa (75 psi), the active fuel
management oil pressure relief valve is stuck in the closed position.
6. Repair, as required.
Test Procedure [ Oil Pressure Diagnosis And Testing ]
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1. With the vehicle on a level surface, run the vehicle for a few minutes. Allow adequate drain down
time, 2-3 minutes, and measure the oil level.
Fig 4: View Of Special Tools: Oil Pressure Gage & Adapter
Courtesy of GENERAL MOTORS CORP.
2. If required, add the recommended grade engine oil and fill the crankcase until the oil level
measures full on the oil level indicator.
3. Run the engine briefly, 10-15 seconds, and verify low or no oil pressure on the vehicle gage or
light.
4. Listen for a noisy valve train or a knocking noise.
5. Inspect for the following conditions:
1. Oil diluted by water or glycol antifreeze
Refer to Coolant in Engine Oil .
2. Foamy oil, which may be caused by a cut or damaged oil pump screen O-ring seal
6. Remove the oil filter and install the EN-47971 (1). See Special Tools .
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7. Install the J 21867 (2), or equivalent to the EN-47971 (1). See Special Tools .
8. Run the engine and measure the engine oil pressure.
9. Compare the readings to Engine Mechanical Specifications (RPO LY5 VIN J) or Engine
Mechanical Specifications (RPO LC9 VIN 3) or Engine Mechanical Specifications (RPO LY2 VIN
C) or Engine Mechanical Specifications (RPO LH6 VIN M) or Engine Mechanical Specifications
(RPO LMG VIN 0) or Engine Mechanical Specifications (RPO LY6 VIN K) or Engine Mechanical
Specifications (RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L9H) .
10. If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following
conditions:
1. Oil pump worn or dirty
Refer to Oil Pump Cleaning and Inspection .
2. Oil pump-to-engine block bolts loose
Refer to Oil Pump, Screen and Crankshaft Oil Deflector Installation (RPO
LY2/LH6/LMG/LY5/LC9)Oil Pump, Screen and Crankshaft Oil Deflector Installation
(RPO LY6/L76/L9H) .
3. Oil pump screen loose, plugged, or damaged
4. Oil pump screen O-ring seal missing or damaged
5. Malfunctioning oil pump pressure relief valve
6. Excessive bearing clearance
7. Cracked, porous, or restricted oil galleries
8. Oil gallery plugs missing or incorrectly installed
Refer to Engine Block Plug Installation .
9. Improper operation of the active fuel management oil pressure relief valve
Refer to Cylinder Deactivation (Active Fuel Management) Oil Pressure Relief Valve
Diagnosis and Testing .
Engine Oil Pressure Indicator Malfunction
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit
Engine Oil Pressure 5-Volt
Reference
Short to
Ground
High
Resistance
Open
Short to
Voltage
Signal
Performance
P0522
1
P0522
P0523
P0521
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Engine Oil Pressure Sensor
Signal
Low Reference
P0522
1
P0522
P0523
P0521
-
1
P0523
-
P0521
1. Engine Oil Pressure Indicator Malfunction
Circuit/System Description
The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor
is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5-volt reference circuit.
The engine control module (ECM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and
provides ground via the EOP low reference circuit. The ECM monitors the signal circuit of the EOP sensor to
determine the EOP sensor voltage is within the normal operating range of approximately 1-4 volts. When the
engine oil pressure is high, the EOP sensor voltage is high and the ECM senses a high signal voltage.
When the engine oil pressure is low, the EOP sensor voltage is low and the ECM senses a low signal
voltage. The ECM sends the EOP information via the serial data circuit to the body control module (BCM).
The BCM then sends the EOP information to the instrument panel cluster (IPC) via the serial data circuit.
Reference Information
Schematic Reference
Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Instrument Cluster Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Engine running, observe the scan tool Engine Oil Pressure Sensor parameter. The reading should
be between 41-448 kPa (6-65 psi).
2. Verify the engine oil pressure, refer to:
1. Oil Pressure Diagnosis and Testing for the 4.8L, 5.3L, 6.0L, 6.2L and 7.0L engine.
2. Oil Pressure Diagnosis and Testing for the 4.3L engine.
3. Oil Pressure Diagnosis and Testing for the 6.6L engine
Circuit/System Testing
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1. Ignition OFF, disconnect the harness connector at the engine oil pressure (EOP) sensor.
2. Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal listed below and
ground:
1. Low Reference Terminal 3 (Gas)
2. Low Reference Terminal 1 (Diesel)
1. If greater than the specified range, test the low reference circuit for an open/high resistance.
If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal listed below and
ground:
1. 5-Volts Reference Terminal 2 (Gas)
2. 5-Volts Reference Terminal 3 (Diesel)
1. If less than the specified range, test the 5-volt reference circuit for a short to ground or an
open/high resistance. If the circuit tests normal, replace the ECM.
1. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If
the circuit tests normal, replace the ECM.
4. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 8 kPa (1.2 psi).
1. If greater than the specified range, test the signal circuit terminal listed below for a short to
voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
1. Signal Terminal 1 (4.8L, 5.3L or 6.0L Gas)
2. Signal Terminal 2 (6.6L Diesel)
3. Signal Terminal 3 (4.3L Gas)
5. Install a 3A fused jumper wire between the signal circuit terminal and the 5-volt reference circuit
terminal listed below. Verify the scan tool Engine Oil Pressure Sensor parameter is greater than
550 kPa (80 psi).
1. Signal Terminal 1 (4.8L, 5.3L or 6.0L Gas)
2. Signal Terminal 2 (6.6L Diesel)
3. Signal Terminal 3 (4.3L Gas)
4. 5-Volts Reference Terminal 2 (Gas)
5. 5-Volts Reference Terminal 3 (Diesel)
1. If less than the specified range, test the signal circuit for a short to ground or an open/high
resistance. If the circuit tests normal, replace the ECM.
6. Ignition ON, perform the IPC Displays Test with the scan tool. Verify that the engine oil pressure
indicator turns ON and OFF when commanded.
1. If the engine oil pressure indicator does not turn OFF, replace the IPC.
7. If all circuits test normal, test or replace the EOP sensor.
Repair Procedures
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Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Engine Oil Pressure Sensor and/or Switch Replacement for the 4.3L engine
Engine Oil Pressure Sensor and/or Switch Replacement for the 4.8L, 5.3L, 6.0L, and 6.2L
engines
Engine Oil Pressure Sensor and/or Switch Replacement for the 6.6L engine
Control Module References for ECM or IPC replacement, setup, and programming
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