2010 Cadillac Truck SRX FWD V6-3.0L Page 1098
瀚慖f not the specified value, replace the Tow/Haul switch assembly.
3. Depress and hold the Tow/Haul switch.
4. Test for less than 1 ohm of resistance between the Tow/Haul switch signal circuit terminals B and A while the switch is depressed.
瀚慖f greater than the specified value, replace the Tow/Haul switch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup, and programming.
* Automatic Transmission Range Selector Lever Replacement (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Shifter
A/T/Service and Repair/6T70/6T75 - Automatic Transmission/Automatic Transmission Range Selector Lever Replacement)
P0089
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.
