DTC P0087 or P0088
Diagnostic Instructions
DTC Descriptors
DTC P0087 51: Fuel Rail Low Pressure
Malfunction |
DTC P0087 53: Fuel Rail Low Pressure
Malfunction |
DTC P0087 55: Fuel Rail Low Pressure Too Few
Transitions |
DTC P0088 51: Fuel Rail High Pressure
Malfunction |
DTC P0088 52: Fuel Rail High Pressure
Malfunction |
DTC P0088 53: Fuel Rail High Pressure
Malfunction |
DTC P0088 54: Fuel Rail High Pressure
Malfunction |
DTC P0088 57: Fuel Rail High Pressure
Malfunction |
DTC P0088 58: Fuel Rail High Pressure
Performance |
DTC P0088 59: Fuel Rail High Pressure
Protection Time-Out |
DTC P0088 5A: Fuel Rail High Pressure Not
Plausible |
DTC P0088 5D: Fuel Rail High Pressure
Malfunction |
Circuit/System Description
The engine control module (ECM) uses commanded fuel pump flow to
determine a desired fuel rail pressure. The ECM monitors fuel rail
pressure with the fuel rail pressure sensor. The Fuel Pressure
Regulator Solenoid 1 is used to control the fuel pressure at the
fuel rail. The Fuel Pressure Regulator Solenoid 1 is pulse width
modulated (PWM). The ECM supplies the voltage directly to the Fuel
Pressure Regulator Solenoid 1. The ECM controls the solenoid by
grounding the control circuit with a solid state device called a
driver.
Conditions for Running the DTC
• |
The DTCs runs continuously
once the above conditions are met. |
Conditions for Setting the DTC
P0087 51, P0087 53 and P0087 55
The ECM detects that the rail pressure is below the minimum
threshold.
P0088 51, P0088 52, P0088 58, P0088 59, P0088 5A and P0088
5D
The ECM detects that the rail pressure exceeds the maximum positive
deviation of rail pressure.
P0088 53
The ECM detects that the rail pressure exceeds the minimum rail
pressure.
P0088 54, P0088 57
The ECM detects that the rail pressure exceeds the maximum rail
pressure.
Action Taken When the DTC Sets
DTCs P0087 51, P0087 53, P0087 55, P0088 51, P0088 52, P0088 58,
P0088 59, P0088 5A, P0088 5D, P0088 53, P0088 54, and P0088 57 are
Type A DTCs.
Conditions for Clearing the DTC
DTCs P0087 51, P0087 53, P0087 55, P0088 51, P0088 52, P0088 58,
P0088 59, P0088 5A, P0088 5D, P0088 53, P0088 54, and P0088 57 are
Type A DTCs.
Diagnostic Aids
• |
A restricted fuel supply line,
a leakage in the high pressure section, too much or too little fuel
in the low pressure line may cause DTCs to set. When ambient
temperatures are below 0°C (32°F), the fuel tank pickup
screen may be iced over from water in the fuel tank. |
• |
High Resistance in either
circuit of the Fuel Pressure Regulator will cause a DTC to
set. |
• |
There are no driveability
concerns associated with the fuel rail pressure regulator unless a
DTC is present. One of the causes of these DTCs is a sticking fuel
rail pressure regulator. |
• |
If the fuel system pressure is
actually too high, a fuel knock and smoke condition will
exist. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EN 34730-1A Fuel Pressure Gauge
For equivalent regional tools, refer to
Special Tools .
Circuit/System Verification
1. |
Ignition ON, observe the DTC
information with a scan tool. Verify that no other DTCs are
set. |
2. |
Engine running, observe the
scan tool DTC information parameter. DTCs P0087, or P0088 should
not set. |
3. |
Operate the vehicle within the
Conditions for Running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
1. |
Ignition ON, command the fuel
pump ON and OFF with a scan tool. Verify the fuel pump turns
ON. |
2. |
Ignition OFF, install the
EN 34730-1A Fuel Pressure Gauge . |
3. |
Ignition ON, verify the fuel
pressure is between 414-550 kPa (60-80 PSI). |
4. |
Ignition OFF, disconnect the
harness connector at the Q18 Fuel Pressure Regulator. |
5. |
Ignition ON, verify a test
lamp illuminates between the ignition voltage circuit terminal 1
and ground. |
⇒ |
If the test lamp does not illuminate, repair the
ignition voltage circuit for a short to ground or an open/high
resistance. |
6. |
Ignition ON, test for 3-4 V
between the control circuit terminal 2 and ground. |
⇒ |
If less than the specified range, test the control
circuit for an open or a short to ground. If circuit tests normal,
replace the K20 Engine Control Module. |
⇒ |
If greater than the specified range, test the
control circuit for a short to voltage. If circuit tests normal,
replace the K20 Engine Control Module. |
7. |
Inspect and repair one of the
following conditions: |
Low Pressure
|
• |
Injection nozzle stuck in open
position |
|
• |
Leakage in the fuel rail
pressure regulator |
|
• |
Worn fuel injection
pump |
High Pressure
|
• |
Fuel injection pump stuck
open |
|
• |
Fuel rail pressure regulator
stuck closed |
|
• |
Restricted fuel
injector |
8. |
If all circuit tests normal,
replace the Q18 Fuel Pressure Regulator. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|