Buick Regal: Symptoms - Displays and Gauges
NOTE: The following steps must be completed before using the symptom
diagnostic tables.
1. Before using the symptom diagnostic tables, perform the Diagnostic System
Check - Vehicle in
order to determine that there are no DTCs set, and that the control modules can
communicate via
the serial data link.
2. Review the system operation in order to understand the system functions.
Refer to the following
description and operations:
- Instrument Cluster Description and Operation
- Indicator/Warning Message Description and Operation
- Audible Warnings Description and Operation
Visual/Physical Inspection
- Inspect for aftermarket devices which can affect the operation of the
instrument panel cluster or the audible warning systems. Refer to Checking
Aftermarket Accessories.
- Inspect the accessible system components or the visible system
components for obvious damage
or for obvious conditions which can cause the symptom.
- Inspect for the proper fluid levels.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent
conditions. Refer to Testing for
Intermittent Conditions and Poor Connections
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom:
- Fuel Gauge Malfunction (with F46 (AWD) ) Fuel Gauge Malfunction (FWD)
- Engine Oil Pressure Indicator Malfunction
- Outside Air Temperature Display Malfunction
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.
DTC Descriptors
DTC P0521
Engine Oil Pressure Sensor Performance
DTC P0522
Engine Oil Pressure Sensor Circuit Low Voltage.
DTC P0523
Engine Oil Pressure Sensor Circuit High Voltage
Diagnostic Fault Information
1. Engine Oil Pressure Indicator Malfunction
Circuit/System Description
The engine oil pressure sensor changes voltage based on the engine oil
pressure. The engine oil pressure
sensor is a 3-wire sensor comprising of the signal circuit, the low reference
circuit and the 5 V reference
circuit. The engine control module (ECM) supplies 5 V to the engine oil pressure
sensor via the 5 V
reference circuit and provides ground via the low reference circuit. The ECM
monitors the signal circuit
of the engine oil pressure sensor to determine if the engine oil pressure sensor
voltage is within the
normal operating range of approximately 1 - 4 V. When the engine oil pressure is
high, the engine oil
pressure sensor voltage is high and the ECM senses a high signal voltage. When
the engine oil pressure
is low, the engine oil pressure sensor voltage is low and the ECM senses a low
signal voltage. The ECM
sends the engine oil pressure information to the instrument cluster via serial
data. The instrument cluster
will illuminate or display the engine oil pressure indicator when the engine oil
pressure is low.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0521
- The ECM detects that measured oil pressure is at least 47 kPa (6.8 psi)
less than or 50 kPa (7.3
psi) higher than the predicted oil pressure.
- The engine oil pressure is outside of a calculated working range
determined by engine speed and
temperature.
- The above condition is present for greater than 10 s.
P0522
- The ECM detects that the engine oil pressure sensor signal circuit is
less than 0.2 V.
- The above condition is present for greater than 10 s.
P0523
- The ECM detects that the engine oil pressure sensor signal circuit is
greater than 4.8 V.
- The above condition is present for greater than 10 s.
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 instrument cluster illuminates the engine oil pressure 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.
Diagnostic Aids
DTC P0521 can set if engine oil pressure is outside the calculated engine oil
pressure model stored in
the engine control module. This can be an indication of improper engine oil
level, poor engine oil
condition, or mechanical engine issues causing lower than expected engine oil
pressure.
Reference Information
Schematic Reference
Instrument Cluster Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEW INDEX
Master Electrical Component List
Description and Operation
- Indicator/Warning Message 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
With UDD or UDC
1. Verify correct engine oil level and condition.
2. Ignition ON.
3. Verify the engine oil pressure indicator turns on and off when commanding the
All Indicators ON
and OFF with a scan tool.
- If the engine oil pressure indicator does not turn on and off.
Replace the P16 Instrument Cluster.
- Go to next step: If the engine oil pressure indicator turns on and
off
4. Verify the scan tool Engine Oil Pressure Sensor parameter is 0 psi (0 kPa).
Refer to Circuit/System Testing.
- Go to next step: If 0 psi (0 kPa)
5. Engine running.
6. Verify actual engine oil pressure is within specified range. Refer to Oil
Pressure Diagnosis and
Testing in Displays and Gauges Component Replacement Reference.
7. Verify the scan tool Engine Oil Pressure parameter is within specified range.
- If not within specified range
Refer to Circuit/System Testing.
- Go to next step: If within specified range
8. Verify the engine oil pressure displayed on Instrument Cluster is within
specified range.
- If not within specified range
Test or replace the P16 Instrument Cluster.
- Go to next step: If within specified range
9. All OK.
With UDV or UHS
1. Verify correct engine oil level and condition.
2. Ignition ON.
3. Verify the scan tool Engine Oil Pressure Sensor parameter is 0 psi (0 kPa).
Refer to Circuit/System Testing.
- Go to next step: If 0 psi (0 kPa)
4. Engine running.
5. Verify actual engine oil pressure is within specified range. Refer to Oil
Pressure Diagnosis and
Testing in Displays and Gauges Component Replacement Reference.
6. Verify the scan tool Engine Oil Pressure parameter is within specified range.
- If not within specified range
Refer to Circuit/System Testing.
- Go to next step: If within specified range
7. Verify the engine oil pressure displayed on Instrument Cluster is within
specified range.
- If not within specified range
Test or replace the P16 Instrument Cluster.
- Go to next step: If within specified range
8. All OK.
Circuit/System Testing
NOTE: Circuit/System Verification must be performed before proceeding
with
Circuit/System Testing.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector
at the B37B Engine
Oil Pressure Sensor. It may take up to 2 min for all vehicle systems to power
down.
2. Test for less than 10 Ω between the low reference circuit terminal 2 and
ground.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for less than 2 Ω in the low reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If less than 10 Ω
3. Ignition ON.
4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for infinite resistance between the 5 V reference circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the 5 V reference circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module, ignition
ON.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- Go to next step: If between 4.8 - 5.2 V
5. Verify the scan tool Engine Oil Pressure parameter is less than 35kPa
(5psi).
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module, ignition
ON.
- Test for less than 1 V between the signal circuit terminal 1 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- Go to next step: If below 35kPa (5psi)
6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and
the 5 V reference circuit
terminal 3.
7. Engine running.
8. Verify the scan tool Engine Oil Pressure parameter is greater than 800kPa
(116psi).
- If 800kPa (116psi) or less
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for infinite resistance between the signal circuit terminal 1 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If greater than 800kPa (116psi)
9. Test or replace the B37B Engine Oil Pressure Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Displays and Gauges Component Replacement Reference
- Control Module References for control module replacement, programming
and setup
READ NEXT:
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.
Diag
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.
Diag
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.
Diag
SEE MORE:
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Diagnostic
System Check - Vehicle
Review the description of Strategy Based Diagnosis:Strategy Based
Diagnosis
An overview of each diagnostic category can be found here: Diagnostic
Procedu
The diagnosis and repair procedures in a GM Service Manual contain both
general and specific Dangers,
Warnings, Cautions, Notes or Importants. GM is dedicated to the presentation of
service information that
helps the technician to diagnose and repair the systems necessary for the proper
operation