2010 Cadillac CTS Sedan AWD V6-3.6L Page 983
Note: Circuit/System Verification must be performed first or misdiagnosis may result.
1. Ignition ON, observe the scan tool fuel pump control module fuel line pressure sensor parameter. Command an increase in the fuel line
pressure with a scan tool. Verify the fuel line pressure increases to greater than 414 kPa (60 psi) as commanded.
瀚慖f the less than the specified range, refer to Fuel System Diagnosis (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel System Diagnosis).
Note: As little as 2 ohm on either circuit of the high pressure fuel pump actuator will cause these DTCs to set. Test the circuits of the high
pressure fuel pump actuator for a high resistance if you suspect a condition.
2. Remove the G18 high pressure fuel pump and visually inspect the lobes on the camshaft for unusual wear.
瀚慖f the lobes appear normal, replace the G18 high pressure fuel pump.
瀚慖f the lobes are worn, replace the camshaft.
Component Testing
Static Test
1. Ignition OFF, disconnect the harness connector at the high pressure fuel pump.
Note: The DMM and test leads must be calibrated to 0 ohm in order to prevent misdiagnosis.
2. Test for 0.35-0.6 ohm at 20掳C (68掳F) of resistance between low control circuit terminal 1 and high control circuit terminal 2.
瀚慖f the resistance is less than 0.3 ohm or greater than 0.6 ohm, replace the high pressure fuel pump.
3. Test for infinite resistance between each terminal and the high pressure fuel pump housing/case.
瀚慖f not the specified value, replace the high pressure fuel pump.
Dynamic Test
Engine idling, command the Fuel Pressure Control to Increase with a scan tool. The Fuel Rail Pressure Sensor parameter should increase with each
command.
If the Fuel Rail Pressure Sensor parameter does not increase with each command, replace the high pressure fuel pump.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Camshaft Removal - Left Side (See: Engine, Cooling and Exhaust/Engine/Service and Repair/Overhaul/36. Camshaft Removal - Left Side)
* Fuel Pump Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service and Repair)
P0088
DTC P0087, P0088, or P0089 (w/LLT)
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 P0087
- Fuel Rail Low Pressure
DTC P0088
- Fuel Rail High Pressure
DTC P0089
- Fuel Pressure Regulator Performance
