Buick Regal: DTC P018B-P018D
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 P018B
Fuel Pressure Sensor Performance
DTC P018C
Fuel Pressure Sensor Circuit Low Voltage
DTC P018D
Fuel Pressure Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The fuel pressure sensor is located on the fuel pipe. The fuel pressure
sensor monitors the fuel pressure
in the fuel line. The engine control module (ECM) monitors the voltage signal
from the fuel pressure
sensor. The sensor provides a fuel pressure signal to the ECM, which is used to
provide Closed Loop
fuel pressure control.
Conditions for Running the DTC
P018B
- DTC P018C, P018D, P0231, P0232, P023F, P0606, P0641, or P1255 is not
set.
- The engine is running for greater than 5 s.
- The fuel pump enable circuit is commanded ON.
- Low fuel level warning not present.
- The DTC runs continuously when the conditions above are met.
P018C or P018D
- The engine is cranking or running.
- The DTCs run continuously when the condition above is met.
Conditions for Setting the DTC
P018B
The engine control module does not detect a normal fuel pressure change when
the fuel pump is
operating. The fuel pressure sensor performance diagnostic provides a means to
detect fuel pressure
sensor output that is stuck within the normal operating range of the sensor.
P018C
The engine control module detects that the fuel pressure sensor voltage is
less than 0.2 V for 1 s.
P018D
The engine control module detects that the fuel pressure sensor voltage is
greater than 4.8 V for 1 s.
Action Taken When the DTC Sets
DTC P018B, P018C and P018D are Type A DTCs.
Conditions for Clearing the DTC
DTC P018B, P018C and P018D are Type A DTCs.
Diagnostic Aids
Using the Failure Records data may help locate an intermittent condition. If
you cannot duplicate the
DTC, the information in the Failure Records can help determine how many miles
since the DTC set. The
Fail Counter and Pass Counter can help determine how many ignition cycles that
the diagnostic test
reported a pass and/or a fail.
Reference Information
Schematic Reference
Engine Controls Wiring Schematics (LTG)
Connector End View Reference
Component Connector End View Index
Description and Operation
Fuel System Description
Electrical Information Reference
- Circuit Testing
- Testing for Intermittent Conditions and Poor Connections
- Connector Repairs
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify DTC U0074 or U18A2 is not set or stored in history.
- If DTC U0074 or U18A2 is set or stored in history
Refer to Diagnostic Trouble Code (DTC) List - Vehicle.
- Go to next step: If DTC U0074 or U18A2 is not set or stored in
history
3. Engine running.
4. Verify the scan tool Fuel Pressure Sensor parameter is between 0.2 - 4.8 V.
- If not between 0.2 - 4.8 V
Refer to Circuit/System Testing.
- Go to next step: If between 0.2 - 4.8 V
5. Verify the scan tool Fuel Pressure Sensor increases or decreases when
commanding an increase
and decrease in Fuel Pressure with a scan tool.
- If the parameter does not change
Refer to Circuit/System Testing.
- Go to next step: If the parameter changes
6. Operate the vehicle within the Conditions for Running the DTC. You may
also operate the vehicle
within the conditions that you observed from the Freeze Frame/Failure Records
data.
7. Verify the DTC does not set.
Refer to Circuit/System Testing.
- Go to next step: If the DTC does not set
8. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector
at the B47 Fuel
Pressure Sensor. It may take up to 2 minutes for all vehicle systems to power
down.
2. Test for less than 5 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 5 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 Fuel Pressure Sensor parameter is less than 1 V.
- 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 less than 1 V
6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and
the 5 V reference circuit
terminal 3, wait 15 seconds.
7. Verify the scan tool Fuel Pressure Sensor parameter is greater than 4.8 V.
- 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 4.8 V
8. Replace the B47 Fuel Pressure Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Fuel Pressure Sensor Replacement - Fuel Feed Pipe (AWD) or Fuel Pressure
Sensor
- Replacement - Fuel Feed Pipe (FWD)
- 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 - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diagnostic Procedure Instructions provide an overview of each diagnostic
category.
DTC Descriptors
DT
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 Descriptor
DT