2010 Cadillac CTS Sedan AWD V6-3.6L Page 793
* DTCs P0090, P0091, P0092, P00C8, P00C9, and P00CA are Type A DTCs.
* A message center or an indicator displays Reduced Engine Power.
Conditions for Clearing the DTC
DTCs P0090, P0091, P0092, P00C8, P00C9, and P00CA are Type A DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Fuel System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Fuel System Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Observe the DTC information with a scan tool. DTC P0090, P0091, P0092, P00C8, P00C9, P00CA, P0685, or P1682 should not set.
瀚慖f a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble
Code (DTC) List - Vehicle).
2. Ignition ON, command the Fuel Pressure Regulator ON and OFF with a scan tool while observing the following control circuit status
parameters:
* Fuel Pressure Regulator Control Circuit High Voltage Test Status
* Fuel Pressure Regulator Control Circuit Open Test Status
* Fuel Pressure Regulator Control Circuit Low Voltage Test Status
* Fuel Pressure Regulator High Control Circuit High Voltage Test Status
* Fuel Pressure Regulator High Control Circuit Open Test Status
* Fuel Pressure Regulator High Control Circuit Low Voltage Test Status
Each parameter should toggle between OK and Not Run or Not Run and OK.
3. Engine idling, observe the Fuel Rail Pressure Sensor parameter with a scan tool. The pressure should be approximately 1.9-2.1 MPa (279-305
psi).
4. Command an increase and decrease in fuel rail pressure with a scan tool. Observe the scan tool Fuel Rail Pressure Sensor parameter. The
Fuel Rail Pressure Sensor should increase or decrease with each command.
5. 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 OFF, disconnect the harness connector at the G18 high pressure fuel pump.
2. Ignition OFF, verify that a test lamp does not illuminate between B+ and the low control circuit terminal 1.
瀚慖f the test lamp illuminates, test the low control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
3. Ignition ON, verify that a test lamp does not illuminate between ground and the high control circuit terminal 2.
瀚慖f the test lamp illuminates, test the high control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
