2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2109
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0521
- Engine Oil Pressure (EOP) Sensor Performance
DTC P0522
- Engine Oil Pressure (EOP) Sensor Circuit Low Voltage.
DTC P0523
- Engine Oil Pressure (EOP) Sensor Circuit High Voltage
Diagnostic Fault Information
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 to the instrument panel cluster (IPC) via GMLAN serial data message.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0521
The ECM detects that the difference between the predicted oil pressure and the actual oil pressure is either less than 47 kPa (6.8 psi) or greater than
50 kPa (7.3 psi).
P0522
* The ECM detects that the EOP sensor signal circuit is less than 0.1 volt.
* The above condition is present for greater than 10 seconds.
P0523
* The ECM detects that the EOP sensor signal circuit is greater than 4.4 volts.
* The above condition is present for greater than 10 seconds.
Action Taken When the DTC Sets
* The ECM records the operating conditions at the time the diagnostics test fails. The ECM displays this information in the Failure Records on
the scan tool.
* The IPC illuminates the EOP indicator.
Conditions for Clearing the DTC
* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.
