2010 Cadillac Truck SRX FWD V6-3.0L Page 917

2010 Cadillac Truck SRX FWD V6-3.0L Page 917

DTC P0089, P00C6, P228C, or P228D (LF1, LFW)

Diagnostic Instructions

* 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 P0089

- Fuel Pressure Regulator Performance

DTC P00C6

- Fuel Rail Pressure Low During Engine Cranking

DTC P228C

- Fuel Pressure Regulator 1 Control Performance - Low Pressure

DTC P228D

- Fuel Pressure Regulator 1 Control Performance - High Pressure

Circuit/System Description

The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 V reference voltage on the 5

V reference circuit and ground on the low reference circuit. The ECM receives a varying signal voltage on the signal circuit.

High pressure fuel is regulated by the high pressure fuel pump actuator, which is a part of the high pressure fuel pump. The high pressure fuel pump

actuator is a solenoid valve. The ECM provides a voltage on the actuator high control circuit and ground on the actuator low control circuit. Both

circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled. When activated, the high control circuit

driver energizes the high pressure fuel pump actuator and the low control circuit driver pulse-width modulates (PWM) the low control circuit to

ground.

The high pressure mechanical fuel pump is driven by three lobes on the camshaft. The ECM uses the camshaft and crankshaft position sensor inputs

to synchronize the high pressure fuel pump actuator with the position of each of the camshaft lobes. The ECM regulates fuel pressure by adjusting

the portion of each pump stroke that provides fuel to the rail.

The ECM monitors the fuel rail fuel pressure sensor and the high pressure fuel pump actuator to determine if the commanded and actual pressure

are within a predetermined range, or if the amount of fuel pressure correction exceeds a calibrated pressure.

Conditions for Running the DTC

P0089, P228C, or P228D

* DTC P0090, P0091, P0092, P0191, P0192, or P0193 is not set.

* The ignition voltage is less than 18 V.

* The deceleration fuel cut-off (DFCO) is inactive.

* The engine speed is greater than 25 RPM.

* The air bag is not deployed.

* The DTCs run continuously when the above conditions are met for 5 s.

P00C6

* DTC P0090, P0091, P0092, P00C8, P00C9, P00CA, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0345,

P0346, P0365, P0366, P0390, P0391, P0627, P0628, P0629 are not set.

* The ignition voltage is more than 8 V.

* The engine coolant temperature is between -100 and +65掳C (-148 and +149掳F).

* The low side fuel pressure is more than 0 kPa (0 psi).

* The engine is not running.

* The DTC runs once for each engine start.

Conditions for Setting the DTC

P0089

The high pressure fuel pump actuator command necessary to maintain the desired fuel rail pressure is +/-2.5 MPa (363 psi) of the command

expected by the controller. The condition exists for greater than 5 s.