P018D
DTC P018B-P018D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 Schematics (LHU) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
Fuel System Description Fuel System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Connector Repairs Connector Repairs
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Engine running.
2. Verify the scan tool Fuel Pressure Sensor voltage parameter is between 0.2-4.8 V.
• If not between 0.2-4.8 V
Refer to Circuit/System Testing.
• If between 0.2-4.8 V
3. 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 ohms between the low reference circuit terminal 2 and ground.
• If 5 ohms or greater
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 ECM.
• If less than 5 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. 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.
• If infinite resistance
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 ECM.
• If greater than 5.2 V
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. 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 ECM.
• If between 4.8-5.2 V
5. Verify the scan tool Fuel Pressure Sensor voltage parameter is less than 1 V.
• If 1 V or greater
1. Ignition OFF, disconnect the harness connector at the K20 ECM, ignition ON.
2. 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 ECM.
• 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 voltage parameter is greater than 4.8 V.
• If 4.8 V or less
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. 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.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 ECM.
• If greater than 4.8 V
8. Replace the B47 fuel pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Fuel Pressure Sensor Replacement - Fuel Feed Pipe Fuel Pressure Sensor Replacement - Fuel Feed Pipe
* Control Module References Control Module References for ECM replacement, programming and setup